Replying to My 2010 setup - questions

So I have decided to buy a pair of Moment Rockers.  I am 5'9" exactly (175.26cm) and weigh about 140 lbs, but by next season I will probably have put on a lot more in muscle (P90X ftw).  So my first dilemma is: do I buy this year and get a 181cm ski, or next year and get a 178cm ski?

Keep in mind the changes they're making to the ski next year:
-Smaller tip profile for decreased swing weight (also less float, which is not so cool)
-Carbon stringers this year (makes it stiffer? I need it to be playful: butters, presses, all that good stuff)
-Super-durable topsheet
-Graphic doesn't suck anymore

I made a thread about whether I should get them in a 171 or 181 this year, and almost everyone said to get the 181, so I'm wondering if 178 will be too short (since the ski is rockered, after all).  If it is, then I'll accept the not-so-hot graphic and get them this year.

Thoughts?