I'm using GT's Links2. It's been modified pretty extensively to get the look and functionality I want. It does take a little coding knowledge (of which I have very little) but I find that it does pretty much everything I want.
I let the script build plain pages of links in a folder, then insert them on my category pages as include files. I've got some pretty big databases, and I keep wondering when I'm going to have to upgrade to the SQL version, but it's working fine so far.
If anyone needs any help with Links2, I may (or may not
) be able to help, but I'll be happy to try.