Currently the rocker only comes in one size - 181 - it is rumored that next year there will possibly be a 174ish rocker, but that would be too short for you. The 181 would be a solid ski.
The rocker means that the tip and/or tails of a pair of skis have "early rise". They simply lift off the ground earlier than a regular ski would.
In a power ski the main purpose of rocker is to eliminate any tip-dive that may occur on a regular ski.
In a park ski (such as the Reno Rocker) the purpose would be to give you a better time buttering, eliminate your chances of catching an edge while on rails, boxes, or anywhere else on the mountain.
Some rocker skis are flat underfoot, and some other still have camber (not sure about the rockers).
I couldn't find any pictures of the rocker on the Rockers, but here are a few skis that have rocker, the Moment Garbones, and the Surface Live Life 2 (which has a HUGE amount of rocker), Line EP Pros, and the K2 Hellbents, which also have massive rocker
Hope that helps