You can get Fatmans from a few "proper" shops – try Peter Tyson as they are an excellent dealer with a good online service.
I've got a Fatman iTube carbon version 2 with QAcoustics 2050i floorstanders and it sounds awesome!!!
If you can get to Herts/Essex/London area you are welcome to have a cuppa and a listen.
You do notice its a lot better with 320kbps files but the valves really make lower quality files sound better than tranny amps – they seem to sound a bit more open and spacious.
I also have a Klipsch iGroove HG for jnr's room and thats a real alternative to a Zeppelin but for half the price – it has a lovely expansive hifi sound with a particularly solid, controlled and deep bass. Try and check one out before you spend on a B+W Zepp.