Im wondering what the different story arc/endings are once I enter the strip. Is it 1) Work with Benny 2) work with NCR 3) Work with Mr House 4) Work with Caesar. Are those correct and are there any other Arc/Endings? Thanks

Yeah, but I wouldn't say they start when you enter the Strip. Your revenge on Benny (or lack thereof) is like a chapter of it's own, THEN all of those groups show their faces.

So theres 4 endings? I ask because I saved right before enterin the strip. I figure I can go either Caesar, House, NCR or me taking over the strip. Just finished securitron in Bennys suite. Then go back to my resave at the Strip entrance and do all 4 without the pre strip stuff.