Unfortunately audio topics around here usually, don't go that far around here. The Dunning–Kruger effect tends to run rampant in any thread involving audio equipment, so out on a thick skin and hopfully a few helpful people will have valuable advice. While my tube knowledge is very very limited, the London power kits do look interesting and seem to have some technical basis behind them.
Though being a guitar/bass amp thing, hopefully it shuts down most the typical retorts the anti audio crowd comes in with.