Do you have natural gas where you are in MA? What are the utility electrical rates in your area? If your electric rates are high, i.e., electricity costs more than natural gas, then you do not want a heat pump as they are slow to heat a pool (without a proper cover) and they do not work well once the ambient air temperature starts getting into the 60's. I'm going to assume that you have heat pumps listed because you don't have NG but I just wanted to check.
As far as heating goes, if you have a free-form pool you'll need to have a large bubble cover cut and fitted to your pool. A 22x42 freeform pool will require a fairly large, irregularly shaped bubble cover which will be a major pain in the rear to put on and remove. The problem for you is, with a heat pump, you absolutely need a bubble cover or else your heat pump will never get the pool temperature up to any significant degree before overnight cooling robs all that heat away. So you need to discuss pool cover options with your builder to see what they can offer.
I have a salt water pool and think SWG's are great. However, most PB's completely undersize the SWG's with respect to pool volume. I have a 16,000 in-ground pool with a Pentair IC-40 SWG. The IC-40 is supposedly rated for pools up to 40,000 gallons and, if I followed the manufacturers guidelines, I should only need an IC-20 for my pool. Well, my IC-40 is just good enough for my pool BUT, when my cell finally dies (lifetimes are typically 3-5 years) I am definitely going to upgrade to an IC-60 (cell rated for a 60,000 gallon pool) because I much prefer to have the larger cell. Retail prices don't change a whole lot on cell size and your PB should be able to get you a cell at a cost lower than retail so make sure you upsize, get the largest cell possible for your pool. With your pool size, you're either going to need an IC-60 from pentair or a Hayward T-15 cell.
And, I agree with Divin Dave, you want an IntelliFlo, not a StarRite. Also, if you go with Pentair, consider upgrading your EasyTouch automation system to 8 relays instead of 4 relays. You never know how you might expand your pool in the future and having extra relays upfront helps.
I would go with PebbleSheen over Stonescapes for the reason mentioned above BUT that depends a lot on the plaster subcontractor. Just because PebbleTek requires their product to be installed by a licensed and PebbleTec-trained installer doesn't mean it's any better (you just get the PebbleTec warranty). The quality and experience of the plaster subcontractor far outweighs and is more determinant of success than whatever specific product he is installing.
Good luck.
Matt