Zero Interest Balance Transfer Credit Cards?

[John Franczyk]

I'm looking for suggestions for a zero-interest balance transfer credit card. Something I can transfer ~$5000 onto for 12 - 18 months. Also, does anyone know if you pay down, for example, only $3000 of the $5000 transferred balance during the zero-interest period, does the card company charge interest on the remaining balance or do they go back to the full transferred balance and calculate interest from there?  Thanks!