Re:
Google it - there are loads of options about if you dig deep enough. You say you'd love to make your own....why not do this instead? It's piss-easy and unbelievably satisfying if you've even some degree of mechanical aptitude, which you probably do if you spend any time messing around with bikes...
I built my first few fillet-brazed bikes with the most basic kit I could find on Amazon, anyone could do the same if they could be arsed....I sincerely wish more people would just to understand there's no mystery about it, it's just a few tubes joined together at predetermined angles. A bikes a bike....build your own, go for it!