We used our favorite tube set Dedacciai Zero Uno for building.
We used slider dropouts of our own project and machining with LF inserts for Shimano Alfine hub and especially eyelets for wires. Spacing for 40mm tyres, two disc brakes make unusual combination.
If you looking for big frame Orlo is good adress. Currently we can do frame up to 74 cm which is in our standard.