Also, I'm wondering about anchoring the patio posts to the concrete. Seems everyone wants to do it differently. One guy says to put some anchor bolts in the concrete when it's poured (not sure how the post is attached to the anchor bolt). Another guy says just drill a hole, put in a piece of rebar, drill a hole in in the bottom of the post and just set it on there. How should they be anchored? We don't get hurricanes here, but we do get high winds at times.

Quick quote generating isn't necessarily slipshod, any more than slow quote generating means better thought-out. In my business I quote $70,000 products (which can have many options) over the phone, using a spreadsheet where I can check off options and spit out a number. Given that, I find it frustrating that some of our suppliers take 4 days to turn around a quote for a $2000 subsystem we use that's much less complicated.

It's useful and efficient to be able to generate quick budget quotes that help weed out people it's too expensive for, instead of spending lots of detailed time on precise lists of materials for people that only have a budget of half that.

So a quick quote could be good or could be bad. No way to tell unless you get other quotes too. And always ask him to put a detailed quote in writing so you can make sure what it includes.

I'd use Simpson post anchors to anchor your posts to the concrete.

Ok, I'm making some progress. I've gotten 3 proposals so far. I have a preference for a company that actually is a lumber company that makes the beams and corbels for a lot of contractors and has been in business for about 50 years. The only real problem came when I asked about the concrete slab, which is the only thing they subcontract out because they don't do concrete. The slab will be 4" with 12x12x24 spot footings on the corners where the posts will be. Two things I asked about were 6 inch mesh instead of fiber, and rebar "dowels" into the existing adjacent slab to avoid getting a step if the old and new slabs don't settle together. He didn't mind doing the mesh, but tried to talk me out of the rebar dowels, saying I don't need it. He then said the mesh and rebar dowels would add $600 to the regular $900 for the slab. I don't know anything about concrete, but I have the feeling they don't really want to do the dowels so are quoted it high to discourage me from requiring it. What do you think?

I should mention that frost heaving is not an issue here as the ground doesn't normally freeze, and is mostly dry sand.

And one more thing. The rebar dowels would be going into the existing 4" slab, which concerns me since I think dowels are normally done in 5" or thicker slabs. Am I risking cracking the existing slab?

I've decided to handle this project myself, and contract with the concrete company and porch company directly. I spoke with the local permit people, and this is OK if I submit drawings for both together. So, now I'm working on the design specs for the slab. This will be a 4" monolithic slab. I can either go with a "turned down edge" full perimeter footing (A.K.A. frost wall), or spot footings where the patio cover posts will be. The spot footings would likely be 12"x12" (or 16x16) and 24" deep. Our frost line is 16". We don't have much of a problem with frost heaving, but I'd like to overbuild it to make sure. Since this will be butting against the existing 4" porch slab which is part of the house foundation, I want to minimize the potential for vertical movement of the new slab. I have ruled out dowels into the existing slab because it's only 4". I believe that to pass inspection the full perimeter footing would need to be deeper than 16". I know the full perimeter footing would cost more due to more concrete and rebar, and labor. The slab is 9'-6" by 15'-6". Pros and cons?

sounds like you'd benefit from hiring a designer.

Yes, that thought had occurred to me.

You might also try posting the concrete question in the Remodeling forum. There are some pros that hang out there that might be able to offer more.