Cool idea. Hope it is successful for you guys.

As others have said, interchangeable components is a key strategy. E.g. Ideally I'd like to be able to choose the size and style of pack and hammock to suit my requirements.

While you are targeting the day-pack/urban use market, I think there is definitely an opportunity to cater for camping/hiking fans. E.g. A 45 L pack and lightweight hammock with an integrated mosquito net and tarp combo would be awesome for overnight/2 night trips. I'd certainly look at buying one if it proved practical and saved me some weight.

I would suggest looking at frameless ultralight backpacks and mimicking similar designs, with the integrated hammock pocket/flap built into the pack's back-pad. Keep it lightweight, simple and high quality you'll likely build a following with weight conscious hangers.

Cheers, TL