Auto vs. Manual Tranny Predicament

[6D9 Matt]

Ok so heres my situation, Im currently looking (and have been for a couple months) for a 69 camaro. At first I was picky, but not Im realizing how hard it is to find a nice camaro. At first I DEFINITELY wanted a manual tranny, then hopefully get AC, 12 bolt, and a certain color. Im looking to spend $25-30k if I got most/everything I wanted.

After having a hard time, Im starting to realize maybe I can do without AC (maybe add a vintage kit later), as well as the 12-bolt (maybe add that or a 9" later as well) given maybe I can save upfront if these options are left off. My question is...

I am planning on dropping in an LS-based 402, 427, or something similar eventually anyway, so the 4 speed Muncie may not hold that kind of power (550 rwhp/rwtq), so is it smart to maybe just save a few bucks up front (and time searching for the right car) and get an auto, then just buy a nice 5 or 6-speed after I find the car? I feel like even if I find a 4-speed car, I may be replacing it before the new drivetrain goes in anyway bc of the power.

Thoughts?

About how much would it cost for labor for a shop to install a manual tranny kit into an auto?