Two good channels is going to cost a lot of money. Typically you might use a stereo pair - Mic Amp - External A/D converter - AES to your digitial recorder. In this set up the external amp and A/D converter are being used on the assumption that even the amps and the A/D conversion on a device like the 722 are not good enough.
The set up I use is Schoeps stereo pair (with various capsules)- Pendulum Audio Tube Mic Pre - Dan Lavry A/D Converter - AES to 744T. The sound that that set up produces is a world away from recording directly to the 744T even though it is an excellent recorder. The quality of each component in the chain is really important, but the the quality of your analog to digital conversion is going to make a big difference.