You know, I just recently upgraded from my trusty 001 to an 003. I got a new Macbook, so I had to upgrade to a newer system and PT8. I will say that machine never let me down, and I was able to produce some really good results with it.
I'm actually using an 8 channel RME a/d/d/a converter with some outboard lunchbox pres and that is what I used with my 001. The first pre upgrades I did were RNP by FMR audio and they were great for the price. I suggest you check that out, if the lunchbox route is too big a leap for you.
The RME and Lucid recommendations are great though. My mom is running an 001 setup in her studio and she loves it. She's using it with 6.4 and is addicted to recording.
I refrain from calling her a Gearlsut though. haha.