Pardon me if I'm hijacking, but I'm going through the same thing. I'm about to start a new record, and I've had the same MOTU 828 MK II for 8 years now. I've kept the MOTU because it's done so well in converter tests: The Ultimate Converter DA/AD Loopback Shootout Thread!
Any recommendations in the $1300 and under bracket that would be a solid upgrade to the MOTU? I've been looking at the Audiofire 8 and the RME Fireface UC. I don't need tons of I/O. 4 channels of analog would really be sufficient, and 8 is what I have now. My primary concern is conversion.