power supplies

[oldboy]

i have just aquired a core udc 20 charger and 2 cell 7.4v lipo but will need a power supply which is where my problem lies lookin around there are so many with varying wattage and ampage values also at vastly varying prices as a man on a budget i dont want to spend to much but also need it to do the job can anyone help out a newbie and advise me at what sort of level wattage/ ampage i should be looking at. thanks very much