A few thoughts:
You will have to change the freehub body if you want to use a SRAM cassette that is a direct match to the shifters. I've briefly used the Rotor 11x36 12 speed cassette with a SRAM system and it seemed to shift fine. No idea if the 12 speed Shimano cassettes, which would be the cheaper option, would work well.
What cranks do you have? You may have to hunt a little to find the chainrings, and I kind of doubt you'll find ones that are "12" speed, but it probably won't matter.
The 16 tooth gap on the front chainrings will be well outside spec for the SRAM 12 speed front derailleur. I don't know if this will be an issue, but the SRAM front shifting has the reputation for being finicky, so it might be a problem.
The only mechanical 12 speed group are Campy, though you could use 11 speed SRAM parts with this hack:
https://ratiotechnology.com/products/upgrade-kits/
I didn't find the 12 speed electronic SRAM shifting to be a great revelation compared to a well-adjusted 11 speed SRAM mechanical set up. I noticed that it did out of the saddle upshifts very nicely, but I personally am as interested in the extra cog as the electronic shifting.
I am not much of a fan of hydraulic brakes and have found little to justify the hassle compared to a quality cable brake with good housing.