Amp for lightspeed attenuator? = $1000 used

I use a Sumo Polaris 310 the early model. The two following models really sound different to me. The one I have to me sounds like a rowland model 1 that I compared it to for a few weeks but with a very slight more liveliness. That is quite good company. Sumo actually had their pre amp with a passive mode so it works well. It has 47k input imp. and a 1.27 input sens. This amp is twenty years old used on average 12 hrs a week. Never had problem with it. But may be hard to find being that old. The 2 following models were redesigned by someone other than the original designer Rich May. So those are really a different sound, a bit bright imo. From what I hear though some day it would fun to try a proper tube amp. I have had tube amps, arc classic 60 and arc vt70, in the past but not with the LS. The sumo when it comes up seems to be asking about 300..I don't know if he still does, Mike Bettinger use to fix and rebuild sumo and gas gear. I understand he did a great job.

George: thanks for all the insight. I can't seem to find the burston 100 anywhere --- would a musical fidelity x-dac tube buffer work also? There's one in the classifieds now: http://app.audiogon.com/listings/musical-fidelity-x-dac-v-3-tube-stage-buffer

Or are there other tube buffers you consider reasonable for not messing about with the signal?

Thanks for all the amp pointers!

I'm having a hard time tracking down the older recommendations. Does anyone have experience with Muse 150s or with marantz ma-700 monoblocks?

Again, I need something ideally that is more than 100W @ 8ohm.

George: the burson 160 is still for sale. Would that work as well as the 100?

http://www.frontendaudio.com/ProductDetails.asp?ProductCode=9999-11288&click=18920

Dddrrreee: trouble is the xdac is a tube ouput stage buffer you will be back in the same boat trying to drive your 10k amp and ?k two times active subs from it. It needs to be a solid state buffer. with 100ohms or less output impedance.

Cheers George