At the moment, GVA,SXF,LGW,DTM are 319, with a couple of 737s left at LGW. ORY and STN will be converting to the 'bus at the end of the year. Others are rumours nothing yet positive. Other crew bases are LTN,LPL,EMA, BRS,BFS,NCL,EDI and GLA. All operate a mix of -700s and -300s, apart from, at the moment EDI and GLA, which are -300s. There are continual rumours about new bases and some bases becoming all -700s but nothing yet in CONCRETE, rumours still abound.
I would have thought that to get a job with EZY if you want one, then the job would be first priority, then the Base, to avoid the expense of a move, then the type, bearing in mind that eventually the whole Company will likely fly the 'bus. If the first two don't bother you then go for the type you want. It is forecast that 737 training will be running down for new entrants and initial courses will be on the bus, but if a 737 base gets short of crews then some are going to have to be trained or converted, aren't they.
Apart from BFS and the Scottish bases, which are limited at the moment, although BFS is getting better, all the other bases offer reasonable choice of routes, obviously the bigger ones, LTN,STN and LGW with the most aircraft have the highest number, but BRS, LPL and NCL do quite well too.