Powder Ski Help!

I really want to get the Rossi S7s in a 168 but they are eeeexpensive!  I found some Scott P4's for 1/2 the price in a 171.  But I am having a hard time understanding what the early tip and tail (or the "protip") means?  Is that more of a camber then reverse camber? or can it be compaired to the Rossi S7s?  They sound like they are a great ski, but I want to make sure I know what I am buying.  I would rather have something with more of a reverse camber then a traditional camber, and I cant seem to find anything specific on the scotts.

So here is the deal line up... i need some advice as to what ski i should get:

Rossi S7 - $640
Rossi S6 - $340
Scott p4 - $300

Or if you have any other ideas for something that has traditional camber underfood and rocker tip and tail that is anywhere from 105 - 120 underfoot and 168 - 175 length let me know!

Thanks!!!!!!