We inquired with half a dozen PB's in our area and while most were right in budget, all bids were flawed in some way. The one proposal that addressed my concerns about yard drainage, utilities and decking was 50% more money

Much to my wife's uneasiness, I might be contracting some of this build myself. I have some history in home construction. I've done concrete work, plumbing, electrical, tile, ect just not for a pool. So I might have some questions.

Here's the design I've come up with. Overall it's about 36'x30' with the main body about 25'x16'. The center is 6' deep and the spa elevated 18"

The things I've done the last month for pool preparation:
I hand dug 10 yards of excess dirt from the yard,
I removed a preexisting pea-gravel patio,
I relocated the sewer lateral line,
I replumbed the house NG service so the meter can be moved to a better location,
I installed a hard piped french drain system around the yard
and I installed about 500 sq/ft (out of 1200 sq/ft total) of large brick pavers. The wife helped

I think I'm ready to get bids on the excavation, rebar and gunite but I assume I need to have a coping selected before hand to determine pool beam height. (the yard is pretty tight). Yes, No?

If I do plumb this myself is there any recommendations on skimmer selection (I assume they'll come with installation drawings). Do I really need a "bubbler" in the lounge area? and how is that plumbed? On it's own return? or just parallel with the pool returns? How about the spa plumbing. Would a single return (make up) be enough or should I install two for water to go over the wall.