Ditch the XT-2, keep the 8100a. Put card 5 in "proof". Run Breakaway, feed it to the Optimod, let the 8100a do the preemphasis and stereo gen. Don't drive it harder than -2 without a card 0. If you have a card 0 in it, the overshoot control is even tighter with a super clean baseband and you can drive it up to -1 on peaks. You'll have all the control and multiband where you need it, and save yourself a LOT of money. Like $12 grand of money.
Of course, if you have the $$, then by all means go get the 8600. But if you want to break even, sell the XT-2, use the proceeds to buy Breakaway and a PC with a solid state HD and have some spare coin in your pocket.
You can also do baseband from a 192khz sound card, but I haven't tried that yet. My hybrid setup works quite nicely.