Reminder - this thread has drifted off topic and is now about using high-power 2A3s or 2.5v 300Bs in the Stereomour.
I talked a little to Dan, and to Mike at Magnequest. It looks like the only suitable and currently available output transformer is the TFA-2004. It can be used with the stock plate choke or the Magnequest BCP-15/50mA or the BH-5, without changing the circuit or tube. It should give a bit more power, 1 or 2dB, depending on the linearity of the tube used. At a guess, no more than 5 watts. Distortion will likely go up at full power, from 3% to 5% if the tube is highly linear (most 2A3s and 300Bs are).
Alternatively, you can use the TFA-2004 with the EXO-003 plate choke running 60mA by using a high power 2A3 or a 2.5v 300B - dissipating 18 watts per tube. This will not increase the power any further, but it will bring the distortion back down to the 3% range.
In small quantities it does not make economic sense to use our regular laser-cut plates. I can have Front Panel Express make you a larger (12" square) plate, drilled for the TFA-2004/EXO-003 combination as well as the stock combination - the cost would probably be $100-$150. Bottlehead could probably sell a larger base kit as a separate item. I don't know the cost, but let's say $50-$100 for a total around $200.
This is not now a standard product, and probably won't ever be. Magnequest may at some point offer specific upgrade iron for the Stereomour, and we may come up with circuit upgrades (I am always working on them!) or new versions, and they may or may not be compatible with this chassis idea. Just wanted to be clear about that!
