I have used the painless wiring universal for a past 66 and am currently using one for my 65. I like them because you can add on other options without having to splice into any wires, like power windows, locks, electric feul pump etc. They are well marked and bundled in groups, like under dash, engine bay, rear lights etc.
XOXO is right, take your time and solder everything. I tried to crimp on my last one and it took forever to work out all the bugs.