I much prefer Blizzard Beach over Typhoon Lagoon for that age. My boys are too young to go in the wave pool at TL by themselves (5, 3 and 2) as I've seen grown men get knocked down by both the waves and other people so that leaves out a large part of TL.
BB has got a great family raft ride - it's really long and we ride it at least 4-5 times every visit. The kiddie area is a blast and the kiddie raft ride is a lot of fun for that age.
I personally think that TL is good for older kids who are great swimmers while BB is geared more to the younger crowd. We get there early, play, have lunch, float along the lazy river, play for another hour call it a day. There are things to do for every age at both parks, but I prefer BB over TL for the younger ones.