Just Make the "Right" Blend of a Breeze and Gossamer Gear Pack and You'll Do Fine
The original Golite Breeze should be the starting point for all lightweight packs. Add more, subtract something, only if you dare! Gossamer Gear got that mostly right, and mostly aimed at upsizing the Breeze, giving it some suspension, while using some fragile but light materials. My early Glen Pleski (spelling?) pack, predecessor to Gossamer Gear, got traded away, but my Breezes are "hold forever" packs.
Based on my experience, the two most important things to add to the Breeze are a sternum strap and simple webbing waist belt. Golite almost, but not quite, nailed the concept with the Jam - but maybe Jardine had design rights to the Breeze that forced Golite to tinker with the Jam and the result was less stellar than the Breeze.
Be sure to use good material. I am not sure silnylon is it - I had the Dawn pack from Golite - it seems sturdy for most uses, but I liked the Dyneema in the Breeze. The one thing I DO like about silnylon is its intrinsic, long lasting water repellency/resistance.
I don't like the "sleeping pad" flaps in the Pleski/Gossamer Designs. Seems brilliant at first, but I keep coming back to burrito rolling the pad and packing my other gear in it. So sizing the body of your new bag to work with a burrito rolled sleeping pad might be a good idea...
Finally, no water bladder pocket. The side pockets are ample for water. I don't like water systems that keep the water out of sight so you don't know how much is left, or put the bottle against my back. I just use large Platy bottles with spout caps in the side mesh pockets....
Other than that I, like many others, wait to see what you come up with. I a sure it will add some new design focus to this niche!
P.S. - come out with a "carry-on" luggage adaptation. Travel luggage is too heavy and over-designed!