Hey Daymon,
I can't think of a reason the 4 10's wouldn't work. THe will have a much tighter bottom end which you will probably like. (4 10's can drop as low or lower than a 15) THe only thing I would for see is that it will have a boost in the mids.
With the tube works stuff it should sound fine. Adjust the eq to your tase and play away.
(I have been in the process of designing speaker cabinets with multiple smaller speakers for steel. They will have a much quicker response than the 15's.)
Good luck and E-mail me if you need more help.
Joe[This message was edited by Joe E on 07 April 2000 at 08:32 PM.]