If you want that GTX 780 BADLY, go for ASUS ROG 780 Poseidon (if you can afford it). It's very cool on load (see Guru3D for its review). If you're looking for SLI, go for two ASUS GTX 760 DirectCU II or if you want SLI like performance, go for ASUS Mars 760. But again, GTX 780 Ti is better whatever you say. Wait for ASUS GTX 780 Ti DirectCU II OC or go for the Gigabyte GTX 780 Ti Windforce 3X, it's not so flashy, though.
Summery:
AFFORDING ON GTX 780: ASUS ROG 780 Poseidon
AFFORDING ON PERFOMANCE: ASUS GTX 780 Ti DC2-OC/Gigabyte GTX 780 Ti Windforce 3X