i'm using an rme fireface400 with faderfox modules and a novation remote le for midi control. i also used the fireface800, which is amazing, but switched to the 400 for portability.
http://www.rme-audio.de/en_index.php http://faderfox.de/
i've used motu 828, ultralite, digi002, ozone and edirol interfaces in the past. the rme interfaces are by far the best i've used
(and the most expensive, go figure). excellent quality converters with which i could actually hear the difference, very stable at low latency settings (a must for real time processing and looping), plus the extensive jitter suppression and excellent software mixer.
my second choice is definitely the motu products, really stable
and very affordable.
live will work well with most any interface that has decent up to date drivers,
but i would suggest avoiding m-audio products(like the ozone i had), based on my experience, bandmates experience(fw410) and info from the live users forum (instability issues, poor latency).
my only attempt at an all-in one controller/interface (ozone) was a complete fail, poor build quality and drivers. not to mention a hot-unplugging issue with that unit was causing dammage to peoples fw ports.
having a dedicated interface allows you the flexibility to try multiple controllers until you find one that works for you....imho, that is just like finding a bass that you like.
tons on the market, but which one will suit your workflow best?
i also like the behringer bcr and bcf midi controllers, maybe the best for the money right now..
http://www.behringer.com/BCF2000/index.cfm?lang=ENG http://www.behringer.com/BCR2000/index.cfm?lang=ENG