Replying to Mountain bikin

i have an 05 kona stuff, and i ride dirt jumps, trails, drops , urban and a little downhill here and there. i am kinda looking into getting a dually frame although nothing over 5 inches. I am thinking maybe the kona howler or cowan DS. how well would these fare in the riding situations i do? and also if i put a 150mm fork on the front of either would it fuck everything up? ( they are both 4 inch rear wheel travel) o and p.s i ride in ontario but may be going to the north shore/ whistler for a week in the summer, and would like a dually for that and general riding. hope you can help and thanks for your time NS!