I'm in the Orient on a trip. Found a guy in my travels who make custom tube amps - mostly SET. He has about six standard design but make many customs for decades. I think he started in the military. I have never owned a tube amp and would be grateful for a bit of help....

He makes stuff from 3.5 watts SET to a custom 1000 watts in a unit that is a large five foot tall rack on wheels.
Locally, his best seller is an integrated SET based with a GU50 tube accurately rated to produce 15 watts - not a typical tube apparently as I don't read much about it. Apparently he likes the tone and say the tubes are very durable. Of course, I'd love to get one of his 50 watt SET using 805 tubes but at over 100 lbs, that's just too hard to bring home.
Currently, I'm asking him to:
1. Use point to point build. He thinks with an extra heavy duty board, the performance is the same as a point to point but does build quite a bit of point to points as most seem to want that.
2. Use silver wiring that he use for his higher end builds.
3. Build using better parts - but there's a limit to what he can get locally. A lot of the foreign 'brand names' could be fakes so he tends to be conservative.
4. I am asking him to have an additional left and right RCA output to route to my subwoofer.
5. Have some kind of fuse to protect the setup if a tube shorts.
Questions for you pros:
1. Would having a RCA signal output negatively impact the performance of the tone? I assume not.
2. Is it possible to have the power output from this amp with a high pass filter above 80 hz (or 60 hz) to match small speakers with the subwoofer? Someone told me somewhere that its as simple as soldering a small capacitor or resistor or something - don't remember.
3. Do you think its worth my asking for a list of the capacitors and resistors (and whatever else) needed and purchase top end parts here in the US, and then mail it? I've never done anything like this.
4. Is there anything else I should consider? Perhaps a different type of tube?
Thanks,
UL
ps: In my travel, I handled and listened to a prototype that is coming out in July that is absolutely fascinating - being able to use a wide range of tubes and have selectable headphone impedence for an exact match. I'll post photos when I get back.