I'll do my usual and throw out the option of the Milab VM44-link mics. Excellent mics, very good price. They've got a high-frequency bump that would probably be good for speech intelligibility as well as for recording at more of a distance.
Overall, I'd say that small, active cable style mics might be easier to cart around for your purposes, and having two separate mics might be more useful for conducting interviews than a single stereo mic.
The Milabs have a street price of $930, so a bit more than $1850 a pair, which might be in your range. There also is a swedish taper on this board (brn2rn) who might be able to broker you a deal and get them for $300-400 less. Just do a search on Milab and you should be able to find the relevant threads.
Also, from a portablity standpoint, you might want to look into the Fostex FR2le, especially one modded by Oade Bros. For about $750 for the recorder + $1850 for the Milabs + a bit more for your bag, stand, cables, etc, you should be able to put together a very nice rig for interviews, home recording, ambient recording, etc for something in the range of $2800-3000 total, less if you can go thru brn2rn.