I'm using Landon's and after putting it in and setting the timing I havn't given it a second thought. I works very nicely!
I think it would be easy to build one from a junk yard distibutor, but for all new internals and to let someone else do the work, I figured I'd buy Langdon's.
There is a tech tip on this site on how to convert an HEI. You should also try a search of this site 'cause people have posted tips that might be helpful.
http://www.stovebolt.com/techtips/hei_conversion.htm
