I went through Dark Horse Performance. Any company that specializes in 5 and 6 speeds into old pony and muscle cars will help you with everything you need.
You have to get another tranny crossmember, do something for the clutch mechinism. I made my crossmember and adapted a newer style quadrant and cable setup. There are a ton of companies selling these conversions. Are you keeping the 87 motor F.I. or going to carb?