to save money and have things 'be easy as possible'
go rectangle, don't have it deeper than 6', go with a liner, the fiberglass pools are cheap for a reason and one of the reasons is that they are cheap.
Spend on the pump. The 'saltwater pool' (I also wanted this option) was a hassle and I converted to chlorine. the saltwater thing is just the way that the cleaning is produced... the salt is converted by a device and it is a hassle... just either stay on top of the chlorine or get a good pool man.
Solar heat, if you can afford it, get it. You'll like it in the summer. Also, get a nice rectangular pool blanket and remember to put it on... the water will be nice all summer and part of the fall.
The liners are reasonably priced, they last AND they are pretty easy to replace after 10 years. (the cost of the water was not my favorite, but oh well.)
Our pool has an attached hot tub and it does have an 8' deep end.... I spent on a really good capacity heater and did not regret it.
Sold the house a few years ago, but ran into the buyer awhile back and he was appreciative of our approach... he has still not replaced the liner and claims it is 'perfect' after 12 years, but I suspect it is probably bleached and in need of replacement.
"Be polite to everyone you meet, but always have a plan to kill them"
-Bubba Ray Boudreaux