TomodachiF:
As you know, the K701/2s & Q701s require an Amp that can provide sufficient current and voltage, and a couple of pre gain settings are surely welcome to get close to the sweet spot of your match. The Q701 needs 3.2 Vrms, that's 4.5 volts peak; At 62 ohms, that's 72 mA of peak current. So the Q701s need a low output impedance and quite a bit of voltage and current. IMO, that's the equation you have to solve first. Once you got a list of the tube Amps that match those characteristics, you can make the money math. Saving a bit more and waiting to get something better always pays off.
Cheers!