Note that the Golite Jam is a frameless pack. Many are not comfortable with moe than 20 lbs. in a frameless pack, although this depends on the individual. Very few like a 25-lb. weight in a frameless pack. What you may want instead is a lightweight framed pack. Here are some examples of framed packs that mostly weigh 2 lbs. or less:

ULA Circuit (about 2.5 lbs) or Ohm 2.0
Six Moon Designs Starlite or Traveler (with the "optional" stays)
Hyperlite Mountain Gear (several packs)
Elemental Horizons Kalais or Aquilo
Gossamer Gear Mariposa or Gorilla

My own recommendation is to look first at other areas for lightening up gear. Have you read the articles on the home page of this site, left-hand column? Chances are good you have plenty of possibilities in clothing (duplicate items) and all the miscellaneous stuff. I know I did!

You might want to look for a lighter tent. 3.5 lbs., especially for a solo tent, is pretty heavy these days. You might want to look at offerings by Tarptent (especially their Notch and new Moment DW, both double wall tents), Six Moon Designs, Lightheart Gear. All these have solo tents under 2 lbs. and some nearer 1 1/2 lbs. They have 2-person tents well under 3 lbs.

Once the rest of your stuff is as light as you want to get it, then assess if you really want a frameless pack. In the meantime, you may be able to lighten your bomber pack a couple of pounds by removing the lid and trimming straps (just be sure the straps are long enough to fasten over all your winter clothing, and hem them after trimming so the buckles won't come off--don't ask me how I know this! ).