I originally started with one of those semi-DIY companies (not Unbound, but similar) where they build a site plan, give you a permit packet, and offer to sell you the hardware in a kit, but I found it to be not worthwhile. They mismeasured the roof via poor quality areal photography, and the BOM they came up with was low to midrange hardware with a large markup.

I just rolled it myself and found suppliers for the panels, inverters, racking, did the roof CAD layout & branch structure, and permitting (single line diagrams + some paperwork) myself. Saved a bunch of money and ended up with a nicer install that way.