Old Grouch (a Member here) has 'em.  Assembled Hellcat  I'd opt for the Large Alice pack, and get some wrap-around horizontal compression straps.  You could do a LOT worse, and pay more.  I would definitely turn the pack inside-out and inspect all the seams.  Assuming the stitching is not blown-out, then DEFINITELY use a bic lighter to sear/melt the frayed edges of the fabric to prevent seam blow-outs.
The Desert camo can be easily dyed with a 50-50 mix of Rit Apple green/Dark Green dye.  See my thread "On Dyeing With Rit Dye" in Tac Gear forum here.

Most of this is discussed in the ALICE Gear thread, pinned within one of the "must know" threads atop the Tactical Gear Forum.  That is a MUST-READ for anyone using ALICE gear.

Tactical Tailor offers all sorts of custom modifications to Alice packs that are sent to them.  Personally, if going that route, I'd suggest at least the Storm Flap, the Stress Point reinforcement stitching, and two full MOLLE/PALS Modular side panels.  The QD buckles modification can be user-performed using field-expedient repair buckles. at less cost.  Don't use black buckles as they are a No-No when seen under night vision devices.   The very useful top carry handle can be made using some 1" webbing and a couple of tri-glide buckles, back-threading the webbing through the buckle, and so locking it in place.  The top carry handle is useful because it eliminates wear on the shoulder straps at their critical attachment point.  If carrying the pack by hand for a distance, simply grasp the side of the frame at the balance point.

One thing that most forget is the ability of the ALICE frame, with MOLLE waist belt, MOLLE shoulder straps, and an ALICE Cargo Shelf, to transport large, solid, heavy objects.  Examples of which are 4X 50 cal ammo cans or a 5-Gal fuel/water can.  You'll also need some straps to secure the load.  None of the plastic frames will do that task.  In fact, very few pack frames will carry such a load.

Having said all the above, at some price point you will be approaching the place where you would be better off buying a gently used MOLLE II (single body) pack and plastic frame.  Dismount the pack and dye it if necessary.  Again, see my dyeing thread mentioned above.

If you are on a tight budget, then go Hellcat.  I know of nothing else that offers the same capabilities at the same price.  You will need to sear/melt the edges of the fabric inside the pack, but that is fairly straightforward, although there is some learning/technique involved.  Nothing most people can't handle easily enough.