Sounds a bit more like a skill issue than a kayak issue. It sounds like your height and weight would fit a Force 4 and a Force 4 is fully capable of playing in the waves. If you're broaching in the waves, I expect that it's an edging issue, but I'd have to watch you paddle to know for sure. If you're just getting started in rough water paddling, you should take a lesson with a qualified instructor before you build a kayak...

that said, I love my Romany for playing in the waves, surf and rocks. I designed the Siskiwit LV as a cross between a 16-foot day boat and a 18-foot expedition kayak.