Can't go wrong w/Montbell, IMO. Everything that I own, I like. I lust after a few other items from them, as well!
A compactor bag should weigh 2.5oz.
A polycro groundsheet should weigh about and ounce for 1, 2-3 for 2 people, etc. I use window shrink film from ACE Hardware for cheap - same material.
Many good poly long johns out there. No need to spend much to get good ones. My confortrel from Sierra Trading Post have lasted yrs, are light & warm.
There's a great Ti pot set w/ pouch & spork for around $30 in Gear Swap right now. I don't like sporks, but if I was looking for a good deal that's it!
For the money I find Golite's quilts hard to beat. Esp the construction and width.