Laptop based keyboard rig - newbie asks for the wisdom of the group

[Jim@an email address]

Hi,

After playing with my first proper band, I discovered what a mammoth
pain it is carrying 2-3 synths, a stand and all the extra boxes and so
on to rehearsals/gigs. Then I saw Kraftwerk on the TV - a MIDI
controller, a laptop, a stand and nothing else - thats got to be the
rig of the future!

I have just got myself a decent laptop with a fast processor and a
firewire interface. Next, I will need a) some kind of audio/MIDI
interface and b) some synth software.

This is where I want to ask you chaps for your opinions and expirience.
What would be a good audio/MIDI interface box to get? What should I be
looking for? The ones I have looked at seem mainly geared towards
either recording or for DJs. I just want to be able to plug in a MIDI
controller keyboard and have zero-latency audio coming out to my amp or
a PA.

Also, am I right in assuming you can run synth/piano/organ emulators
(several at once?) on the laptop and play pretty much as if you had a
real B4/Moog/Oberheim but without the weight and the hassle?

Thanks for any advice,
Jim