I had to get my oil changed and brake fluid changed so I thought why not change the calipers to the BMW Performance BBK that I bought off of an e90post member last year while I'm at it.
I was a little hesitant that it may require additional work but I spoke with Mike @ Maranello BMW
while I was picking up oil just in case I needed any additional parts. He informed me as long as I have the rotor and calipers, everything will bolt right up as the caliper already comes with a built in adapter to space out the caliper.
I also read this DIY
which I strongly suggest if you're doing this upgrade as if you don't use the new heat shields, you'll have to trim/cut your OE's.
I also am not
using the brake pad sensor and tied it out of the way as I'm aware of when my brakes need to be changed and don't want to spend money on a sensor every brake change; seems silly to me.