I have used this distributor with great success in the past and being all new it is a great deal.
http://www.summitracing.com/parts/SUM-850001R/
I have a used HEI that I too scored at a wrecking yard for $20 (20 years ago) that I ultimately rebuilt with new bushings and springs. I installed a curve kit along with an MSD module and coil and it has never failed to fire and perform as expected.
If you like the small cap look I can't recommend the Pertronix kit (as mentioned by others) enough.
When I built my V-8 Vega the Motown 415ci crate motor I used came with an MSD HEI but it wouldn't clear. I ended up installing a stock points type distributor with the Pertronix "Flamethrower" kit and an MSD Blaster coil and it worked perfect all the way to 7K rpm.
Either way you can't go wrong.. but don't think the stock GM HEI won't fit... you just need to install the distributor with the cap removed.