>Also, this pincremental requery performs well, but I am only querying about 300 records. Not sure this would perform well on a very large data set.

Book mark this for when you get a little further along:

http://msdn.microsoft.com/en-us/library/ms752348.aspx

Don't think it will help when you have a huge dataset, but it should help when you have already loaded a full dataset.

I haven't played with it yet.