Here's a bunch of points to consider.
Micro-stutter:
The GTX7xx cards are the first cards I've ever recommended for a multi-GPU setup.
PSU:
You can Google that with benchmarks, but probably a quality 850W for 2xGTX760.
POINTS:
1) I recommend MORE than 2GB of VRAM. VRAM is not added in SLI so you'll want EACH card to be 3GB or greater. It won't matter for all games, but for some it will and who knows how VRAM usage will change soon now that PS4/XBOX ONE's come out with 8GB (Shared).
2) I usually recommend the BEST, single-GPU card you can get then SLI if that's not enough. You're in a weird position. At 5760x1080 even 2xGTX760 isn't enough for many games unless you turn down visual quality (to maintain 60FPS). On the other hand the GTX770's are a lot more money.
Based on the cards available today, I'd be recommending THIS setup but I imagine it's just TOO EXPENSIVE for you:
2x (GTX770 4GB)
Of the 4GB cards available, I'd probably recommend the EVGA with ACX cooler and backplate. It's academic as it's likely too much money. That's a total of $1000 plus tax.
3) MONITOR:
This likely doesn't interest you, but I prefer to game on a single, high-res monitor. I have a good 27", 2560x1440 monitor. You can find a quality one for about $600 (Dell for one). I play most games at 1920x1080 and a few at 2560x1440 (most games look nearly identical at both resolutions. I play SC2, Diablo 3, Torchlight and Dragon Age Origins at 2560x1440.
Only a handful of games won't run at 1920x1080 at maximum settings on a single GTX770. Of those remaining games, you can generally TWEAK for full quality.
I've tried gaming at 3x (1920x1080). I far prefer my single large screen.
WHICH CARD?
I prefer Asus or MSI, but the only 4GB 760 is from EVGA (stock cooler). I'd WAIT for a better 4GB version.
SUMMARY:
- GTX700 series for SLI
- BUDGET?
Basically, as I said you're in a weird spot if you wish to play at 5760x1080 at 60FPS. If you want high-res gaming you need to PAY a lot if you want full quality. Play at lower frame rates, or sacrifice quality? These are decisions you'll have to make with a 2xGTX760 and demanding games.
My FINAL advice, if you're set on a 2xGTX760 setup, is to WAIT for quality 4GB cards (and of course, TWEAK your settings to achieve the best quality vs frame rate. I run all games at 60FPS). You'll also need to ensure proper CASE COOLING. Front case fan intake, and if possible a large SIDE FAN, all motherboard controlled for speed.