Akitika Amp + Cheap tube pre-amp

Planning to build my first speaker Amp with the Akitika gt-102 Z4. It’s a class AB, but apparently sounds like a class A amp at 50 wpc.

I’m planning to pair it with a heavily modified FX-Audio Tube 03 where I will replace the tubes, op amps, capacitors and volume pot.

Has any toyed around with either of these two items? Would really love some input.