I pulled the receipt from mine, this was done at K&M in Raytown, MO which I think is one of the best shops in KC.
Valve Job with oversize valves $150
Street Port Job $250
Install Guides $80
Install Exhaust Seats $52
Parts and supplies $175
I provided bare heads, valves, springs and retainers.
Total bill was $765.
The street porting job was pretty limited. Since then I've seen better work done by a guy named Scott Vincent for about the same money. Another good person for iron heads is Les Schmader.
http://www.lesport.8m.com/
Also be careful of the late head castings like C8AE-H and D2TE-AA, I think they have the low exit exhaust port and may mismatch with your headers. Definitely check that before you have the work done. If you want the high exit like the edelbrocks and early heads look for C4AE-Gs, C6AE-Rs or earlier C1AE-As
Good luck, Chuck