cycloholic: Yeah that is basically it. Bolt length depends on frame thickness, Shimano supply bolts for 25mm frame thickenss (LCR018-D) should be that (can not confirm that on 100%, I dont have my frame yet

) as standard with calipers, if you need something else you need to buy separate and shimano rear 160mm adapter is sold separately also (Shimano SM-MA-R160D/D) it does not come with a frame.
so basically you just need to buy goupset with calipers and then just Shimano SM-MA-R160D/D adapter and you should have everything you will need.
I have no idea how Sram does it

.