As for cash in advance, I think most would advocate that in the current climate - you risk far too much by putting up a large chunk of cash from the outset. Most organisations understand this, although they may well offer you a better deal if you are willing to take the risk.
Specific to Flying Time, they are a lovely bunch down there. They have 3 DA40s flying at the moment, and 1 DA42 as well as a rather nice Aztec. Instructors are all nice, and although I tend to fly solo down there, I have had a couple of check outs with them and wouldn't complain. For CPL/IR, I would perhaps not be quite so keen. I'd say the club facilities are adequate, but I come from an integrated training background where the facilities were fantastic, so perhaps my expectations there are too high! Be aware that the DA42 sim is not there yet, think it's a bit behind schedule. However, they can arrange fairly competitive rates (particularly on an hour-building rate - I get a C152 for £45 per hr) and shoreham as an airfield has the NDB only approach plus the new RNAV approach, with access to an ILS probably closest at Lydd. Go down there and meet the guys, have a look at the aircraft and get a feel for it. Only you will know whether it is right for you.