Master MIDI Keyboard & Soundcard for Pure Data

Hi,

I'm thinking about getting a master keyboard for use with my laptop
running synths on Pure Data (like MAX/MSP but free). I'm thinking of
61 keys with a medium weighted action, lots of knobs to twiddle and
assign to whatever I want, aftertouch, transpose, mapping the range to
different patches, and sustain (any other things I've forgotten that
could be handy?) Also what are ribbon controllers and are they any
good? Around £100-150 is my budget and it should also be fairly light
and portable (I also play guitar which means even more to carry for
gigs): any ideas?

Also, I'm going to need a new soundcard. I'm looking at the
Soundblaster Extigy (an external Audigy) which is not supposed to be
brilliant but is external (a must for use with a laptop) and around
£100. Just wondered if there's any serious competition and if this
will provide at least adequate sound with low latency? I'm running
WinXP if it's relevant (though if I really get into this I might
finally use something good like Linux).

I'd really appreciate any help you can give. Cheers,
Stefan