Hi,most chargers with a standard size USB connection on them,should be OK.In UK look in TKmaxx etc,for iPOD type ones.
Only prob you might have,is some devices,need Data + & - s USB connections shorted in the charger,Sony might be one(forgot but think it is?),iPod as well?
Bought couple for iPods(for Sony use) from TKMaxx & been OK(got odd old ones in the house,that don't work thou).
Prob not needed:-
USB standard Voltage is 5v.Amps wise should be OK(don't need much).
Try not to get a high ampage one,1A or whatever,especially if its a Linear charger(heavy,copper wires etc).It will work OK,its if you get a prob inside your device,short etc(it will try to supply that current,linear can even exceed its stated current).Mind if you have a prob,device is prob broke anyway
(could get very hot thou).Most for iPods should be OK anyway,rating etc.
Interest waning on getting a Official Sony Leather in UK,coping OK with cheap silicone one,might upgrade that thou
(one with carabiner maybe,good reports on here).
Cheers BOB