Its ok.., you will need some development investment to link into domino, as out of the box the connectivity between notes and domino.doc is pretty naff. (Next version 3.5 is better but that not out till q3 2002.
There are several big names on the market, we looked at some, and initally choose common store, but after 6 mths finally found out that it would not meet all (or 60 %) of our requirements, so ditched that in favour of domino.doc as the project timescales where so short.
Whatever you look at, make sure you get your requirements in stone with the company / consultances involved, and ensure that it meets what you require,