Pre-amp for MG3.6/Bryston 7b combo

Any suggestions for pre-amp from owners or listeners of MG3.X/BRYSTON 7b amp combination? I am not wanting to make a mistake. Local dealer suggests Theta CasaNova because of built in dac. However I already have a theater system and have no intention of using this for anything but music. I am not opposed to purchasing separate DAC. Budget is $5000 for Pre-amp/Dac. I have no problem with purchasing used equipment. P.S.-Dealer wants me to purchase Theta Dreadnaught in stereo or 4 channel Bi-amping instead of Bryston 7b. Ideas on that?
I agree with you that this should be a 2-channel system. With the 3.6 and bryston amp...what interconnects and speaker wire are you using...and you mention you have a transport already....these would have impact.. For what it's worth I have had 1.6, 3.6 and MG20...and have liked high-current solid state for the amplifier..and an excellent tube pre-amp...seems to be a good combo for the Magnepans.
I have MG 3.6/Bryston BP-25MC/2 Bryston 4BST/Bryston electronic crossover. I use HT ProSilway MK II and HT speaker wire. Bi-amping made a MAJOR improvement to my system in a room approx. 19+ X 28+ with a 14 ft cathedral ceiling (lg room) and there is more than enough power to drive the system to very loud CLEAN levels. I would recommend Bi-amping to anyone. Bi-amping with the 7Bs would be perhaps better but in my room somewhat over-kill, but..... If you don't use Bi-amp set up use bi-wire to MG 3.6 as that made a big improvement with only one 4B-ST. Better, I'm sure, with 7Bs.
Whatjd. I have a CD player now-no transport. I have been trying to buy a Levinson transport. However, a friend suggests I wait a few months to see if the sacd or cd-a format high-end manufacturers will come out with a transport that is digital out for those formats. The Maggies have been on order and should be in this month. I thought I would try different cables and speaker wires once the components are purchased. However, I would appreciate any suggestions. The Maggie dealer suggests Kimber speaker wires (an 8 wire version) and Wireworld Balanced connector (particulars unknown). Suggestions?
I agree with the bi-wire or bi-amp suggestion. I have found the front end source and interconnects to have more impact on the Magnepans than speaker wire...but is is always best to have a great source. The DVD-Audio/SCAD thing is a whole other story/thread...I wouldn't hold my breath on that one. Try not to bite off too much at once...get the 3.6 use what you have...listen, read, learn...and make other purchases when you know what the weakest link is...and start with that....I have had 1.6, 3.6 and MG-20. Gotta head to work.. ..but I will share some of my "front end" and cable thoughts later....just don't change too many things at once...the chance for error goes up.