The "Hayward S180T92S 18-Inch 1 HP Sand Filter System" looks like a good, complete option.

I'd recommend several things:

1. Amazon usually accepts returns on defectives very easily . . . but be READY to install, and check everything out, so you can return PROMPTLY if needed. Hayward is usually pretty good out of the box, so hopefully you won't need this.

2. Get a timer to run with it. On a 15' pool, you will not need to run 24/7.

3. Upgrading to 2-speed on your own opens a can of worms you probably don't want to get into, on a tiny system like this. And, with a timer, the savings won't be huge. (Hayward catalogs a 2spd version of this unit, but I couldn't find any for sale.)

4. Get a valve you can throttle:
1.5 Hayward Industrial threaded PVC ball valve
1.5" PVC nipple
The pump may have too much flow, especially on backwash.Throttling it will not only reduce flow, but will reduce electrical usage somewhat. If you do NOT throttle, you may lose sand each time your backwash, AND you may 'force' dirt through the filter during normal operation. If you throttle enough so you do NOT loose sand during backwash, you probably have throttled enough to get good filtration.

CAUTION: do get the nipple. PVC ball valves can be 'stiff'; you'll need the strong nipple to 'turn against'. Put the nipple directly into the pump discharge port, and the valve on top of that. Also, ball valves trap water when open or closed. To winterize, leave the valve in a PARTLY open position.

Good luck!