Brain25 and I have rather different experiences it seems. Given proper brazing I see no issues with making one's own fork. Actually the set up and alignment is the greater issue with most home made forks I've had to deal with.

As to the frame design and the lug angles- the first step is to design the frame and see what the angles are then see what lugs and shells are available in what angles. The cast sockets can usually be tweaked a couple of degrees with little problem. Beyond that more aggressive socket mods are required but still doable. Perhaps not the best first frame method...

I would strongly consider looking at fillet brazing if the angles get too far from the shells and lugs options. Also I would suggest using bronze for any modded sockets. Bronze is far stronger across the gaps that poor fitting tubes have in tweaked sockets. Andy.