Well, I don't know a think about avodart, but from what I've seen fluridil(sp), it looks like it's very promising.
However, since it is a topical, you're going to really have to balance putting it in along with getting your application of minoxidil in. If you think you can do it, I say go for it. I'm probably going to take up fluridil soon myself.
I'd say get on propecia, but I'm assuming you've gone down that path already (and if you haven't, I really suggest trying it since it is very effective at maintaing your hairloss).