2 weeks ago you wanted an FS, now a custom rigid ti? Do you already have the Ventana?
You'll now see a long list of everyone advising the builder they have deposits with or have already received a frame from. Maybe there are some superclyde-specialized custom welders out there, I wouldn't know. I would say for a superclyde an overbuilt stock frame might just be the ticket. Gather knowledge while you're out there riding, maybe you'll even find a $400 is well good enough, cash left for diamonds for the missus.