Is this Card Good for SLI ?

My thoughts on SLI is don't do it. But yes, the GTX 660 Ti is very capable of SLI. Performance-wise, it beats a GTX 670, a GTX 680, and almost to a GTX 690. Just make sure your PSU can handle it.

I don't know what you mean by "run well" in a case. If you meant if it'll fit, then yes.
 
If you have the spare cash get a good GTX 670 and overclock. Otherwise a pair of GTX 650 Ti Boost will put you ahead of the GTX 680.

Make sure its the Ti Boost version, not just 'Ti' or 'Ti OC'
http://www.mwave.com.au/searchresult/650%20ti%20boost/view-20/sortid-1/display-list/page-1

SLI will run very well, at times exceeding 200% performance of a single card!
You might occasionally bump into games that dont like or support SLI, but they are few and unlikely to be some modern big title high end game.

If you want a single card and will not be adding another in the future, you can also consider AMD cards which can provide similar performance at a lower price.

Like a HD 7950 is a lot cheaper than a 670 but can be easily overclocked to approach performance of a 680. The HD 7970 Ghz competes with the 680 but is also much cheaper.