Faster leveling shouldn't be the issue, which one is more fun to play for you should. Zerkers are pretty nice and have some well rounded skills, SB's have more situational skills so they can be a bit more flexible in certain areas.
As for buffer, if you go SB you'll definitely want Haste and VR so I'd recommend a warcryer...until you get 3rd class then the SE you'll want for Empower and VR and can buy Greater Swift Attack Potions if you plan on hunting in non-herb areas.
For Berserker a warcryer would get you all the way through even into 3rd class. Unfortunately Chant of Victory is kinda expensive for solo'ing whereas Prophecy of Wind is much cheaper.
Agree... SB works better with a SE if you like to use your magic skills while hunting, which is the recommended way to go. And ofc... zerk levels up faster ^^
Again :D i'm pretty sure it depends on playstyle... why you want evasion for pve, for example, if you can have a SE healing you, recharging you to keep true zerk on pretty much all the time? get VR4 and criticals too ^^ It's all about taste :P
although, Soul Breaker with focus rapier is very good, and if you begin an attack on non-aggro mob with a Shining Edge at it's back can maximize damage. Soul of Pain magic crits always nice too :P
PS for some who may not know, Shining Edge is similar to dagger skill in that it has higher chance to land from behind the person/mob (attack their back), similar to Deadly Blow.