Thanks for the replies guys.

I realise all frogs are different, but are they likely to be up all night, every night, or just the odd bit of noise?

I think if they are as easy as white's to keep, I would prefer the milk frogs, but the smaller enclosure and easier keeping of the horned frog (as well as them being quieter and diurnal) keeps making me reconsider.

Are they really going to keep me up all night every night?