Hi,
You're not going to find too many commercially available polypyridines. The synthesis of many of them are a little tricky, but a lot of very elegant chemistry has been developed.
Try a google search for these authors: C. Fraser (Virginia tech I think)
G. Meyer (a lot of work with carboxylate "anchors")
B. Loeb (Catholic University, Santiago, Chile).
I will try to dig through my old grad school stuff and find more.