I didn't read thru all that, but as a student I wouldn't be thinking downsize yet. I'm 210 lbs and transitioned to that, Sabre 2 210. In fact, I still fly it at over 300 jumps. I'm real ready to downsize if I had teh green, but I don't and I can wait. I can appreciate thinking ahead, but don't let a budget make you buy smaller just to save a buck down the road.
Buy a canopy no smaller than you weigh. Buy an older one that is in good repair, so you won't have a lot in it, then sell it and you might even make money on it or break even.
The with that money, line up a good container set up that will allow downsizing, but I would say to abandon this, "downsize me" attitiude.