Switching MOBO and gpu question(s?)

First:
MOBO
GPU

I was thinking of getting another card for two-way sli, but I would need to get a new MOBO as well. Should I get another 770 or just upgrade my card to something else?
Since I'd need to get a new MOBO for sli compatibility, would I run into any problems switching motherboards?
Also, if I do go sli, would I need the same card, or can I do a 2 GB 770 and a 4 GB 770, or a 2 GB 770 and a 780?

I'm not sure what other questions to ask, but if you have anything else to say, please do. Also, if you have any suggestions for MOBOs, list them in your comment.
Thanks in advance.

 

You shouldn't run into problems when switching to a new mobo, but make sure your old components are compatible with it.

To run SLI both GPUs have to be 770s, but one can be from a different company. There's no point in getting a 4gb edition because the 4gb will be limited to the same specs as the 2gb. That being said, I would suggest getting the exact same card you already have.

Also two 770s will draw quite a bit of power, I would possibly get a new PSU (depending on your current setup). A 750w PSU will power you PC without any problems, but if you plan on overclocking your CPU or 770s, then I would recommend one that's 850w+.

Good luck with it!