Well, thanks for the advice, everyone.
Ken, that's quite the rundown of stereo mics. The mp3 samples in one of those links sounded amazing. Eventually I decided against going the dedicated stereo mic (or M/S, with its hypercardiod mic) route, because I can't imagine what else
other than drums I would ever use them for. As for mono vs stereo overheads, you know me: when it comes to production I'm all about the needless excesses

. I put an honest effort into finding some cheap ribbon mics (localy; I don't wait), but came up bust. Seeing as those Nadys don't appear to cost any money at all, I may still pick some up down the road just to fill out my mic cabinet.
In the end I went for a matched pair of NT5s from a local shop (as well as an absolutely killer new mic stand: 1.5 kilo adjustable counterweight, telescoping boom, all the grips have locking teeth. But that's another thread. Anyway, now my vocal mic hangs down in front of me from above, making me feel a little like Rush Limbaugh). I spent a big chunk of the weekend messing around with different recording setups, before settling on a sort of modified
Glyn Johns-y type thing. It's a configuration that looks really wrong but somehow seems to work great. X-Y didn't work for me at all. Anyway, it's too late to record a demonstration, but I'll see what I can do tomorrow.
Also, it turns out that my audio interface actually only has 4 inputs, so that solved my should-I-mic-the-hi-hat-or-the-toms dilemma: neither!