distributor choice

For best price/performance ratio and simple hook-up, it is hard to beat the $45 new "ready-to-run" HEI distributor on ebay. Many posts here if you search.

If you consider an engine electronic engine controller down the road, an 8-pin GM HEI module might be smart since some ECU's can control the spark timing via those. No need to fool with distributor springs, just type in the curve you desire.