looking for tube amps to power top-end of speakers

Guys,

Looking for some help in deciding what type of tube amp or amps to use for the top-end of my JBL 4343 studio monitors. I am currently powering the speakers with a nice solid state amp, but want to bi-amp or tri-amp the speakers to smooth out the top-end. I will use the solid state amp I have to power the woofers, but am looking for advice on what amp/amps to use for the top-end. The speakers can be bi-amped/tri-amped. I welcome suggestions on new requipment, but am willing to purchase vintage tube gear as well. I don't have a large budget, but want to stay around or under $2500.00. Stereo tube amp or a pair of mono's? I woulkd also need, I assume, an external crossover to do this?? Advice needed for this too. PLEASE HELP!!!!! Thanks,

John