The AC delete spacer is available from JNzTuning.net or any Mitsu dealer if you have the part number.
Check at partsbase.org and build the car, AC delete, it will show up where the bracket would otherwise be.
The bolts that hold the intermediate shaft bearing to the block have the proper diameter "shoulder" to aligned the bracket to the block and keep the shafted aligned in the differential with no binding under all situations. I bought the bolts from my local source, RtMRacing, but they are a cheap insurance for knowing nothing is taken to chance. They do have the proper washer setup also.
One other point on the bolts, is that they have a taper right at the end, with no threads, essentially a shoulder, and this is to compensate for the way the holes were tapped into the block. Regular bolts do not accomplish a proper fit because they will be too short for the designed location due to interference before they lock down or they don't have the proper shoulder for alignment.
I have heard of some people using the hardened washers and proper bolt strengths, with no issues to date, but it's a $15 equation that cars making twice the rated factory output should not be taken lightly.
My opinion, due to the fact that I've had enough issues with older Mitsu drivetrains that bearings going or parts binding are the last thing I want to have go under mountain driving conditions or spirited highway use, or other.