It depends on how much stuff you're comfortable bringing in, but for a small mic preamp, I'd look at the Naiant littlebox. More info on naiant.com and also in the Retail section of ts.com and the preamp section. Jon/mshilarious is a member here and is the designer/builder of the littlebox. Not the absolutely most compact mic preamp you'll find, but close. Unlike options like the aerco mp2 or EAA psp2, the littlebox is easy to come by and very affordable -- sounds great too.
Pair it with the new Sony M10 recorder or the Edirol R09HR.
BTW, I've never heard about anyone frowning about discussion stealth equipment on ts.com, just stealth techniques.