Welcome aboard.

You're going to have to define what "retro" means to you, e.g. what period in time are you trying to emulate. I say this because a 6AL box is not very retro to an old geezer like me, but if you're a young enough stud then 10 years ago could mean retro to you.

There is a world of choices out there. Can you live with a shiney, milled aluminum look. Would you rather have an "as cast" aluminum look, or would you paint whatever distributor housing you use? What kind of cap would you like? I don't think a genuine magneto would be of benefit on a street driven rig, but if you like that look there are electronic distributors made to imitate that look. So, you need to provide more info.

Sorta like what happens to you if your i.d. is indicative of what your job is.......................more info is better.