Sounds like a solid plan. IF you want to spend some money, a set of Edelbrock heads would be the best investment you could make. Instead of throwing money at a set of old iron heads buy a set of these. Take off about a 100lbs with these and an RPM intake and you'll be good to go. You won't have to worry about upgrading heads again.
Here is a link to Rock n Roll Engineering. Lots of info, good reading and Bruce will work with you on setting up your block for a long life. He has some good advice for clearances and building these motors to live on the street.
http://www.pontiacpower.com/
Mark