.45 suppressed, 10mm unsuppressed (if mags isn't a problem). You don't want to fuck with suppressing 10mm or .40 for that matter, trust me, not worth it. In short, the gas volume from 10mm is far more than 9mm or .45 and on top of it is a high pressure load. So unless you want a giant can, go with the .45 or 9mm, they suppress better. 9mm is high pressure on par with 10mm, but it uses far less powder and therefore far less gas is produced that needs to be slowed. Consider how loud a 147gr. 9mm is anyway and the size of can it takes to suppress that. Really think you can suppress more than twice the gas in the same size package for the same performance? Really? .
Not to be boner killer, trust me, I wanted one so bad I was going to have one custom made since they didn't exist at all in .40 or 10mm a few years back. 10mm is my FAVORITE pistol caliber, period. I have both Glocks and a 1006, all tanks that can handle full max and over max loads, especially the 1006. I love everything about the ten, especially how forgiving it is with handloads compared to .40. But after extensive conversations with engineers and various mfg.'s, and going back to the board and just looking at the math since that's my gig, it was obvious from the start that 10mm isn't worth suppressing. Can it be done? Yeah, but it's never gonna be as good suppressed as the others. And if it is, it'll need to be overbuilt. Expect it to work more like a rifle suppressor, so you may as well just stick with 155's loaded to the max and since it won't matter, just go with the highest KE.
Plus, you state you plan on firing this 90% suppressed... Assuming you want maximum suppression, penetration and diameter of wound channel, it's kind of a no-brainier: .45 is heavier by 30 grains, larger by .05 calibers or about 1mm, is already subsonic at normal loadings. There are also expanding bullets for the .45 that will actually expand at those velocities too, good luck with that and the ten, without velocity they tend to either close up, plug up or do nothing at all. May as well use FMJ, better penetration. 9mm's claim to fame is that it suppresses well with 147's which use like a pinch of powder to propel it, has low recoil and high capacity lending itself well for that kind of duty. 10mm has none of these attributes the .45 and 9 possess, so why would you want to suppress it? Now a moderator may make sense, I use those a lot myself but I have as many cans as I do rifles. A moderator will take the full power 10mm load and take down the dB's to a more manageable level and they are only about 5". Keeps length down on PDWs, doesn't blow my eardrums out so I'm deaf for a week without earpro and still allows full power ammo. Now that's a different scenario but it's the only scenario I'd consider with respect to suppressing a ten.
I learned a LOT trying to suppress my tens. Now and again I still think how cool it would be, but then reality kicks in. Basically, when it comes to handgun calibers, what works best is .22, 9mm and .45. .380 has a bit of a following but I think it's more movie oriented (James Bond) than real. There is a reason most cans are built for that and it's not just because they are the most common calibers. And were I to go with the Kriss, and I have considered it, I'd have gone with the 9mm despite wanting the .45 or desiring the 10mm.
Since I can't get my hands on a proper PDW like the MP7, I use a 8.5" .300BLK AR w/HK stock, FF carbon fiber delta tube and iron sights along with a TBAC Ultra 5 for mine. Same KE as .45 with subs, but due to the cross sectional density of .30 compared to .45 in similar weights, the .30 has FAR more penetration and also FAR more range (nearly 400m in fact). So pistol caliber rifles have completely fallen by the wayside around here, but we DO have five Blackouts, all but one an SBR.
Good luck, hope this helps because I've been there, done that. Up to a point anyway.
The 10mm gives it a separate purpose as a hog/hunting platform but 9mm and 45 certainly get the nod for pleasant shooting suppressed. 
