360 Magnum Budget Build Recommendations?

Hey guys! I'm 16, and building a 1970 Duster all by myself.
The guy I got it from swapped in the magnum but never finished the work, and it's a POS, not in a position to spend a few grand yet for an engine swap, so what would you recommend doing?

I plan on purchasing these parts when I get my paycheck.

http://www.compperformancegroupstor...roduct_Code=20-601-9&Category_Code=LACAMRFHRT

http://www.summitracing.com/parts/edl-5076/overview/

http://www.summitracing.com/parts/edl-14073/overview/

If these aren't what you would suggest, can you recommend something around the same price?