Just got one for my outdoor kitchen earlier this year. FWIW, to answer one of your questions- I have two taps.
To answer another question- I wouldn’t really worry about how long the beer will last in the keg if it is properly installed (assuming you are drinking regularly, of course).
My set up is a little different but I keg my homebrews and there’s nothing like fresh draft beer at home. No fancy kegerator, just an old fridge that can fit 2-3 cornie kegs (which are the old 5 gallon soda kegs) or a single standard 1/2 barrel 15.5 gallon keg. I just use cobra head taps on the kegs so I don’t have mounted taps because I’m lazy, but there are a lot of things online that show you how to drill through the side of the fridge and mount actual taps for way cheaper than a commercial kegerator. It just depends on if you’re just looking for draft beer at home or want a show piece as well. If you want a show piece, buy a commercial one. If you just want drsft beer at home, get an old fridge.
I know commercial ones can come with multi tap towers. I think your best bet is to get 1/6 barrel kegs which are about 5 gallons instead of 1/2 barrel kegs because you can have more variety and it’ll be gone quicker. Where I live that’s easy since most breweries, particularly small ones do the 1/6’s, but I guess it depends on where you are. I agree with John, that if it’s under pressure and you keep the lines clean, you can keep them a couple of months easily. But I generally go through 5 gallon kegs in less than a month with no quality issues. If the beer does sit for a week or more untouched, just make sure you dump the first half pint that comes out since that’s been sitting in the draft lines and might be off.
You might also find breweries in your area who will fill homebrew corny kegs like they fill growlers. A couple of them in Portland do that. Drop it off one day and pick it up a day or so later (Hopworks used to have set days for drop off and pickup). But beware that corny kegs and commercial kegs use different fittings, so you might need multiple tap and CO2 lines and fittings.
You can buy a new kegerator (counter height with a “tower” above for about $1,300. They can be made to hold up to three 1/6 barrel kegs (these are called “sixtels”). You can probably find one on Craig’s list for $800-900. If you want to build one yourself, you need to find an refrigerator with a flat floor (almost all new fridges don’t have this, so it will probably be an old one) to put the kegs on. You should be able to get all the parts you need to build it at More Beer in Concord (there may be a closer place). They can also give you all sorts of advice as well.
A couple of things to keep in mind. 1) your beer lines should be 5 to 6 feet long. This is probably longer than they need to be, but in order to minimize foam, you need to slow down the beer flow and adding length does this. 2) if you won’t be pouring a beer for a while, turn off the CO2 to the kegs. You should be running between 12 and 15 psi from your regulator, while the beer is carbonated at between 9 and 12 psi. If you leave the CO2 on, you end up with over-carbonated beer and more foam. 3) I highly recommend sixtels because you can have a variety of beers and because, as Zina mentioned, you can go through a keg faster. A keg should keep for up to three months but it will taste better and fresher if drunk sooner.
Charlie, they’re probably fine. How many taps do they have? You really want one with three taps, and it would be expensive to retrofit one. Another thing to look for is whether it includes the CO2 tank and regulator. If you have to buy those things, you’ll spend about $100.