Barrows pures are trash, take it from me.
In 2008, when berserker pures were undoubtedly the best pking build, I raged and got 70 defense on my perfect berserker pure account once they removed the wildy. 2 months later, I started up another berserker pure and never looked back.
80-99-45 with Chaotics/Turmoil/Yak/etc at 100-105 combat is pretty much undefeatable, pair that with cheap pking sets (400k at edge, 1.5m in brid) and you have yourself a volatile account. I've pked well over 3B since the introduction of BH/PvP, and another ~500m since Free Trade was released within the first month (I have since quit scaping)
The account I got 70 defense on is still 70 defense (93-99-70 at 108 F2p Combat) and I can't stand to pk on that account. I suggest staying 45, but that's just me.