The answers to your questions are:
yes
yes
yes

I understand the features, but no where can I find, who I can buy one from. Who would know?

You can purchase online at their site: http://www.controlledenergy.com/. Probably can locate a local resaler such as Home Depot. Good Luck.

I have the Aquastar 125FX and would advise caution if you are on a well.The pump cycling on and off can cause moderate to bad temperature fluctuation and in the shower that can literally be a pain.The cure is a neat gadget called a cyclestop valve which will add $100-$180 cost to the deal.Just tweaking the system didn't work.

I installed one that we got from ******* . It has worked flawlesly now, and I am on a well also. the pressure through it is a little weak though since it is going from 3/4" pipe down to 1/2", so I cant use it for the whole house. It does work nicely though for filling my new Jacuzzi whirlpool tub, and the shower gets hot water for as long as I want it, also great for filling my water bed, no more waiting for the water heater to recharge. As long as your system is properly sized for the house you wont have pressure fluctuations. We have a 4 bath home and the pressure tank is huge, so the pressure stays steady at 60 PSI with or without a pump. One of the nice things about it, you can put it anywhere and since they have a power vent kit for it, you dont need a chimney either.