what the right size is for both chopping and light duty work is very personal.
i got a fallkniven S1 and like it, because of the good grip, quite heavy for it size ( feels strong, so you will have confidence doing hard jobs ) and good edge holding. Its not to big nor to small for mosts tasks, but it's not for a lot of splitting and hacking ( to small for that ). i suggest to borrow "survival" knife from friends and test them out ( if they let you ) or go to the store and feel how the knifes feels in the hands before getting one your self.

note that i carry more knife's with me wenn going somewhere than just the S1