if your boy friend is the typical spin fisherman or baircaster that fishes from the bank then any decent hiking shoe or boot with good sized lugs should do the job.
if he is a fly fisherman or spends a lot of time in the river then he needs wading boots. when it comes to wading boots there is one company that is miles ahead of the competition in durability, comfort and traction, Simms is by far some of the best gear you can buy, I have a pair of G3 boots that have out lived the last 3 pairs (combined) of wading boots that I had before. although felt is usually the best sole for traction studs are a must. some come studded and for the ones that don't you can get screw in studs. Simms streamtread sole is almost as good as felt, screw a set of hard bite carbide studs in and they are awesome, I picked up a pair simms new guide boots to replace my g3 while they go back to be re-soled and I like them so much I doubt I'll be using the g3 again.
Simms does make sandals and shoes also, designed to be used as normal shoes and sandals as well as wet wading (no neoprene socks or waders required).