How much space do you have now? A two tank type softener will need a space along the wall of roughly 30" and out from the well about 18-20". A low priced and low quality big box store type (GE, Kenmore, Whirlpool etc, all built by Ecowater with the same parts except GE uses a different motor) will take a little less space along the wall but come out away from the wall a bit more. They are very hard to work on if needed. And they usually only last 2-4 years before having to be repaired.
I suggest any properly sized two tank softener using a Clack WS-1 control valve. That control is the easiest to repair and should last
5-15 years before repair is needed. The warranty is 5 years. Those big box store brands have a 3 year warranty on the whole softener! The tanks of a two tank model sold by independent dealers, as opposed to Culligan, Kinetico etc., have 10 year warranties. And IMO the quality of the control valve is critical to service free operation of the softener because that's where all the moving parts are. The Clack has the fewest parts of all controls, 5 and only one moving part in the water stream. You having never seen one before can replace any part in less than 15 minutes. It is a DIYer's dream because it was designed to be the easiest to repair for the dealer.
If you buy over the internet, you will save, in some cases, thousand's of dolars compared to a local dealer's price for the same softener. And anyone with the desire and a few common tools can install their own softener in 3-4 hours.
To learn how to correctly size a softener for both salt efficiency and the SFR (service flow rate) your family and peak demand water flow rate gpm requires, see the sizing chart and calculator pages on my web site.
Gary Quality Water Associates
formatting link