If you are going to work on razors and knives you will want a broader selection of stones, mainly because of the size of the knives and because of the necessity of an ultimately keen razor.
Razor stones are special because they are not only fine but they cut very fast, this is necessary because if they are not fine enough they will not shave well, and if not fast enough (highly gritted) with the light pressure we use when honing razors it would take too long for each razor.
Knife stones are usually larger all around and will withstand a heavy handed routine necessary for knives, and knife stones are not normally as fine as razor stones because they first, do not need to be, and secondly the pounding and scraping that a knife edge goes through in normal use, a razor sharp edge will begin to breakdown within minutes.
You were asking about a suita for razors, maybe a pre-finish stone. Honing a progression of stones for razors is necessary for restoration from bevel setting stages on up. Some of us have a two stone progression and go from 1k directly to a finishing stone, but many fellows use a nagua progression, a pre-finishing stone progression or even several stones lined up as a progression. I would suggest that a nagura progression that can include both Shiro Mikawa Nagura and or tomonagura slurry or elements of other stones would be considered to be the most professional standard. A progression establishes and maintains throughout the honing session an edge that is built on solid steel. The 1k to finisher does give a shave ready edge but it is so closely based on the 1k stones scratch pattern than there could be, in theory, structural factors that underlay that super keen edge that might create some jeopardy regarding the tenacity of the edge.
A single stone that covers all of the tasks of: bevel setting razors, pre-finishing razors, finishing knive edges should be based on a knife stone model if you take into account the factors from above. This stone would be a medium hard stone that in the 5 or 5- range, very fine in the 5 range, sized to fit the type of knife, and easily maintained so it can be lapped for razors when necessary. The grit richness that determines speed could be in the 5 to 5+ range. Sharpening knives is a heavy process that with the right stone can go quickly especially if the stone, like one in a hardness range of the lower 5′s is used because the stone is sheds dull used grit particles while revealing newer sharp particles.
This single stone could be a first step in building a flexible progressive stable of stones, one you could build around but it is unlikely that it will be your one and only middle range stone. I suggest that a tomae stone instead of a suita stone will feel the most comfortable under your razors and knives as “that single stone”. There is a page to my website that I have been developing but it is not yet linked to my website, it is devoted to knive stones and there is one stone there that you might want to try, #1103. This tomae is very smooth but cuts fast because it is grit rich but also medium hard. If you wanted to test it, with a deposit plus postage I could send both the #1103 and the suita #1108.
Testing two stones side by side is very revealing, plus you have your Ozaki there already to test against these two others. I think it would be worth both of ours efforts to do this if you have the shop time to manage it in a week or 10 days. Each of the stones are priced and perform similar, and after testing you can send back one or both if you choose and all it will cost you is the round trip shipping in a Medium Priority box. I will always pay shipping for an outright purchase, but for testing the cost is on you. I have this same arrangement with a few other customers for different reason, but my main idea is to copy in my own way the way that these unique stones were retailed in Japan where the buyer/end user had a chance to bring his own tools or test his own razors on a group of stones to look for compatible combinations between his steel and their stone. The more you get into this the more you realize that with both natural and synthetic stone, there are symbiotic relationships between stone and steel. Almost any combination will almost always work, but combinations that really, really work well are special. The burden is on the stone to perform but the user is in the drivers seat, and when things click it takes a lot of stress out of the process and this allows the driver/user to not only get the same job done quicker but also allows him more flexibility to express technique and professional judgement calls.
Busy shops who specialize in particular steels or techniques find it efficient to match up larger stones that have a longer shop life with the normal tasks that are specific to their work. Blacksmiths choose the steel they forge, but they also choose the stones in their shop tailored to their favorite steels, and stones that are thick will have a longer shop life thus minimizing the burden of shopping for and testing replacement stones when their old ones get thin. Natural or synthetic is not the point, it is efficiency and quality that is primary. Not every stone works for every steel but for a smith or sharpening shop, they narrow down the possibility of failure or loss of production time by repeating past good experiences with certain combinations and repeat those over and over again. Like with antique Sheffield steel softer stones tend to work better and 20th C. German steel benefits by using harder stones. It can even fine tuned down to certain blade makers all though not usually necessary unless you are working with that bladesmith directly.