Lots of guys at shops don't know their shit, I'm alway skeptical (although many really do know their shit, not trying to knock shop guys). Just mentioning it so you take recs with a grain of salt.  One guy told me that at 6'3, 180 lbs and as an expert all mountain skier I couldn't handle 189 Hellbents (which I had already owned for a season). He recommended Sir Francis Bacons in 184 for me and I got to laugh in his face when he told me he skied Pocket Rockets.
I don't think Domains come longer than 179. But K2's 179 is much like any other company's 183 or so.
As for ON3P, they make my favorite skis. K2 is my second pick. I would suggest looking into the filthy rich (dedicated park ski) or Jeronimo (all-mountain ski). Both of them are really sick, and really fun skis. I'm sure you would like either, but I would probably suggest the J-mo