Should apologise to uphillbothways for this as I was quoting the price of the EIE, not the EIE pro.
I've decided not to bother with the Akai EIE - it seems like nobody has used/reviewed them and I don't want to risk it.
Starting this thread has made me sit and think through what I really NEED, as opposed to what looks funkiest and I realise that, for my modest requirements, I would get away with something like the Focusrite Scarlett 2i2 (as recommended by uphillbothways). It looks simple (like me) and, if I wanted to bung my old Novation Nova or JV1080 onto a track, it's only a case of unplugging/plugging in a few leads.
That said, as the PC comes with TI Firewire as standard, something like the Saffire Pro 14 would give a lot more I/O options for only £40 more. The downside is all the mucking about with software mixers/routing options. I'm not too technical and I never had the foggiest clue how to use the EMU Patchmix software on my 0404 card!
Thanks to everyone for their thoughts and interest.