Well, again, then it really depends on the kind of music and demands it imposes. The Elf could work, but before I dived into it, I'd want one question answered (which I raised on another thread here about the Elf): How are the false tones on it? If it has good false tones, then it IS usable for a broad variety of music in the way that you envision. I've used my 1924 Buescher in community band, and tend to do so on "patriotic occasions" (4th of July, Veteran's Day, etc.). I've also used it in Tuba Christmas. The intonation isn't unproblematic on that horn, but it does work and with some effort plays reasonably well in tune. The false tones are great, and so it plays chromatically down to the pedal Eb (and lower). For Tuba Christmas I can use it to play either the Tuba 1 part (where's it's happier) or the Tuba 2 part (which is a lot more effort).
If the Elf does likewise, then it could suit your purpose, but I haven't seen a response to my question about it. I note also that for some years Jim Laabs has been selling a horn that appears virtually identical to the Elf (called the "Gentleman's tuba"), but I also have no idea of what its false tones are like.
Gary Merrill
Wessex EEb Bass tuba (DW 3XL or 2XL)
Mack Brass Compensating Euph (DE N106, Euph J, J9 euph)
Amati Oval Euph (DE 104, Euph J, J6 euph)
1924 Buescher 3-valve Eb tuba (with std US receiver), Kelly 25
Schiller American Heritage 7B clone bass trombone (DE LB K/K10/112/14 Lexan, Brass Ark MV50R)
1947 Olds "Standard" trombone (Olds #3)