Thank you all for the input, you are all right in the line with what I was thinking.
I guess, the only problem I have is that right now I jump 190 and feel comfortable with it, and think that I could handle 170 low performance with in next 50 jumps, my exit weight would be around 190-195 (such as Silhouette or Specter.) I was assuming that used canopies would be easier to pack, plus if it is a seven cell packs smaller too. Also,on Mirage's web site, it says that 7cell canopies can go 1 size up than what is stated in the sizing chart. But than again, I am no rigger.
Thank you for the input. Any further help would be appreciated. "Nothing in this world worth having, comes easy"