I would advise against it. After 25+ years in the restaurant industry, I assure you there are very good reasons most restaurants don't own their own soda towers, but 'lease' them from either Pepsi or Coke. Granted, the 'leases' are very inexpensive, but the soda concentrate you are committed to buying from them forever, more than makes up for shifting maintenance (beyond daily cleaning rituals) , calibration, and repair away from the individual (or franchise) restaurant's responsibility. Yes, fountain soda is a huge profit center for restaurants, but that assumes volume sales. Typical home usage would not be cost effective. This doesn't even consider the CO2 you need, and all that associated equipment (tanks, hoses, and regulator).
Not trying to be a downbringer, but I would really research this more before pulling the (soda) trigger.
This is all IMO, and of course, YMMV.
edited to add: both soda towers and soda 'guns' ( what you would see a bartender using) require running the hoses at the bottom of an 'ice well' to ensure proper serving temperature, so factor that, and the cost of the icemaker, and the required drainage / plumbing / maintenance into the total cost.