I wouldn't discount the 243. I know a lot of folks who swear by the cartidge. If he's 9, get a 243 now and then a 30-06 or 308 later. The recoil on the 243 is light enough to keep him from developing a flinch but the impact is plenty for deer. And as far as recoil goes, you might find this interesting:
http://www.chuckhawks.com/recoil_table.htm