Wow, the gig got postponed way out!!! It's great having backing tracks to practice over. I use my floor pedal with it's built in drum beats and looper to create backing tracks on the fly which is really convenient. One of the best pieces of advice I ever got was to always practice to a metronome or drum beat. The drum machine never tires and it's ALWAYS right in time :-).

With your amp project, are you building both the amplification and power circuit? You have to be really careful with power circuits since you are dealing with AC input voltage that can kill you. Tube circuits are even more dangerous - 600V is nothing to mess with!

Anyway, glad to hear your gig is still on. And definitely post some audio or video when you can! I'd love to check out what you've been doing.