JB,
Absolutely get a pre, pre and A/D or pre w/ A/D. You make the jump to a nice set of mics, you better spend the bread on something that will help keep the signal clean though out the chain. You have to ask yourself a few questions:
what type of recordings so you see yourself doing in the next year? by that I mean stealth or taping allowed?
what do you wanna spend?
If you plan to stealth mainly, get one of two things..... a MMA6000 pre from DPA (if you have the DPAs terminated in the stock micordots) or a dual modSBM (mic and line mod, if you have DPAs with some sort of aftermarket batt box)...the other option is seeif freelunch will make you one of those mini dongles (cheapest route) for the MT....but the MT is a bit lame in the analog>digi conversion....you will eventually want to get something external.
If you plan to do some taping in a taping allowed situation, get a UA-5 (modded). The cheapest way to get a all in one box....but not very helpful for your DPAs unless you get some expensive adapters.
Hope it helps
ANDY