The best of that kind of thing, IMO, is the tonelab LE. It would do what you want of it.
+1 (in fact you beat me to it :lol:)
They've launched the ST, which comes in cheaper. It
seems to have more amp models (or variations on the 11 in the LE? I can't tell from what I've managed to read so far), it also has USB connectivity (LE doesn't, but you can connect to a PC easily via MIDI and an interface). However, the ST seems less flexible for live use to me - the LE has the ability to "open up" a patch with a footswitch, and then you can use the main footswitches to turn effects on or off in that patch - on the ST you would have to cycle between patches (ie if you want to turn chorus on/off, you need to set up two patches, one with, one without, and switch between them).
I've never used the LE live, but based on my recording and home use of it over the last 12 months I definitely would give it a go. I'm doing the equivalent of running it through a PA in my living room (mixing desk to mid/cheap 100w powered speakers), and as long as I can turn it up enough, I
love the sounds I get, much better feel than an amp at the same volume... The only thing that would worry me would be getting enough monitor to feel like I'm playing an amp - I get that in the living room, but in a gig?... gwem must be solving this in his live rig - but I suspect that with the line-up you're dealing with you might not need that much power anyway?
I'd also happily use my POD XTLive in the same way (less convinced of it's reliability though), and at a pinch my POD 2.0 - but I don't like those models as much as the XT models. The pocket POD I believe (and therefore the Pocket POD Express? dunno) is based on the POD 2.0 software, but with minimal tweakability - so if it's anything like the presets in the POD 2.0, er... wouldn't want to use those :lol: