I guess it depends on what you're looking to do. Rebuilding a vintage bike can be pretty expensive. Are you wanting to put more into the engine build, or are you just looking to build something with a stock motor? I prefer putting more into my engine builds. I recently bought a vintage Bird mini, and it's gonna cost a lot more for me to get this thing on the road than I thought. I probably would have been better to just buy a used Doodle (I really want an old style DB). I like the looks of the Azusa kits. I can't speak for their quality because I've never build one.
What will you be doing with this bike? Off-road stuff? Mainly street riding? This all matters. Also, how big of a guy are you? My bird is so small! I fit better on my DB (new style). I'm going to bend up some steel and build a frame for me, but I have free access to a shop with a mill, lathe, mandrel bender, etc. I'm not a fab guy, and my welds are terrible. However, I have buddies that will do that for me.