I believe they stopped making them 2013-2014? Small 1 gallon corny kegs are available that fit in your fridge, but the 2.5 gallon ones are the same price and will also fit on the bottom shelf of a standard fridge. Add a picnic tap, 5' of hose and get a CO2 bottle and you're ready to keg. Note you don't have to leave the CO2 hooked up all the time, you can top off the CO2 when you notice the pour rate diminishing.
Its not the perfect arrangement, but if you can't get a dedicated keg cooler you can make it work.
If you decide you are done with homebrewing you can always sell the small corny kegs, but if you bought the tap-a-draft, its pretty much worthless on the used market.