Well, if you want to be near your lectures then the Victoria Park campus would probably be best but the Fallowfield campus is more sociable, I mean all your mates will probably go to Fallowfield at night cos that's where all the parties go on. It can be a drag trekking from Victoria Park to Fallowfield so in social terms I have to recommend Fallowfield, there's a bus like, every five minutes from Fallowfield to where your lectures will be so it doesn't matter that you're not really near the university.
I have only looked at catered accommodation on the open house day so I'm afraid I can't give you information on that many halls but if you're looking at the Victoria Park campus then Dalton-Ellis is good for ensuite, St Gabriel's also has nice ensuite rooms but it is all girls and it's quite 'twee'. On the Fallowfield campus then Woolton Hall is lovely (it's my first choice!) I believe that Sheavyn House also has the kinds of ensuite rooms you are looking for.
Good luck with deciding!