Like I originally stated, my old handhelds and marine gps's had WAAS capability. Looking at the new Garmin handhelds, they too still have WAAS. So if you need it, then you can get it in a very inexpensive unit...
https://buy.garmin.com/en-US/US/p/87768#specs
But with the all the new Garmin Edges able to additionally use many of the other satelite based navigation systems besides just the GPS system, isn't that sort of SBAS like? And won't that make your reception a little better in your area?
I don't know how widespread WAAS systems are now. But since they are ground based, unless there is one in your area you'll probably not have any better accuracy. Their signal will be even further attenuated by trees, buildings and terrain it must pass through.