where can I find a good selection of blank lugs (that look almost like pipe elbows) with room to make some interesting shapes?

I have some lug like what youre describing, if you send your address, I'll send you a set of lugs and you can maybe use them for your project. Lugs are for building exxon grafteks.

The PCD-123 lugs have lots of room to carve. http://bikelugs.com/p-lugs.html