SLI GTX980 eVGA FTW and Gigabyte GTX980 G1

Solution

Yes, you can SLI these, and you can use any bridge you want.
However, keep in mind that these cards have different boost clock speeds. While they will run fine (I ran a reference AMD 7950 and sapphire 7950), you will run into problems when overclocking. I could not achieve a stable OC because the two cards had such different boost clocks. You may have a better experience, but that's the trouble I had with different clock speed cards.

Yes, you can SLI these, and you can use any bridge you want.
However, keep in mind that these cards have different boost clock speeds. While they will run fine (I ran a reference AMD 7950 and sapphire 7950), you will run into problems when overclocking. I could not achieve a stable OC because the two cards had such different boost clocks. You may have a better experience, but that's the trouble I had with different clock speed cards.
 
Solution