I don't think the stock tubes sound that bad, and also don't necessarily believe they need biasing. If you choose to crank your gain way up (which sounds great for practice, but "fuzzes out" in band situations,) then some feedback can be expected even with actives. The Hush peadl is the industry standard, but I use a Digitech GNX4 and before that an old ART ECC and if set up correctly, I have been happy with both of those. I am not saying to go out ang get a $500 GNX4 for a noise gate, but rather if a multi-effect unit can give satisfactory results, a stomp-box noise gate will most likely provide even better results. I think knowing how to sett up your noise gate for your particular gain level etc. is the key.
Bryant