Response Time on LCDs doesn't matter at all. I still have a 5 year old Samsung SyncMaster 170MP as a secondary monitor. While the graphic quality isn't as good as the newer LCDs, I never had any issue with ghosting or other effects associated with slow response time. Heck it doesn't even have a single dead pixel, and it's been in use almost 24/7 for those 5 years...
Using a SyncMaster 193T as a main now, again no issues with ghosting and the response time is 25ms too iirc. Using it to play HL2 too, so it's not that I just play MMORPGs :p
And I'd definatly go with the digital one, that's what is going to get you a picture quality boost.