I'd say, if you do re-pitch, use the same yeast that you used for your primary/secondary fermentation. I had the same question for my first lager that I'd had lagering for 6 weeks. I brewed it with fresh MN Snow for my water source so I didn't want to mess it up during bottling. I ended up using nottingham dry yeast per my LHBS's suggestion. I wish I would've used Bohemian Lager yeast. I think that the nottingham gave it a fruity flavor that wasn't present before bottling. Still a tasty beer, but my suggestion is, don't re-pitch with yeast. If you do, use the same yeast as in primary/secondary!
Cheers...and please anyone correct me if I'm off base.