Odds are the answer is: yes-- 2 kegs will fit. That being said....
Take a tape measure to a Best Buy and measure the interior dimensions. A typical half barrel is just under 16" in diameter. A typical corney keg is 8 1/5 to 9" in diameter. If the kegerator is made to give you any wiggle room at all for a half barrel then you can definitely fit 2 corneys and could possibly fit as many as 3 into it. Height is a non-issue for this--- if a half barrel with a sankey connector will fit then a corney keg will fit.
If you decide to go this route: commercially available kegerators will have a standard American sankey tapper, generally. This isn't a bad thing, really, because if you set it up right you can throw the occasional commercial keg in the fridge for parties or special events, etc. when you don't have enough (or don't want to share) your homebrew. There are in line quick releases available at morebeer.com that I've been very happy with.
http://morebeer.com/product.html?product_id=6715 That's the kit, I bought the individual parts from the site to set it up just the way I wanted it.
I have seen that particular unit at cheaper prices than that, although with a good sale you might be able to get it at as much as 25% off that price.
As for why one would want to buy a commercial unit instead of crafting their own: there are several good reasons why someone would want to pay a little more and get something that is mostly ready to go.
a) not very handy -- which makes a big difference with the finish work.
b) don't have or have access to many tools -- building projects get really expensive really fast if you have to buy tools to make it happen
c) don't have lots of time -- some folks don't have the time it takes to plan for, acquire and assemble a fridge
d) have a deadline -- if you're trying to get things set up for a wedding or a party and are running into a crunch sometimes buying is the best way to go.
e) want it to 'fit' into my existing house -- unlike many homebuild jobbers, the commercial stuff is right at countertop height and looks sharp and professional. If SWMBO needs the appeasement of 'it's gotta fit in' then commercial might be your only real option
f) getting a good price -- sometimes you can pick these things up from 'former bachelors' who's SWMBO has declared that the keg cooler has to go-- you can often get them for a song under those conditions.
g) don't want the trouble of having to figure out the whole thing for a 'one build' item-- let's face it, if your first fridge meets all your needs, the stuff you had to learn to complete the build could very well be never used again
Now, if none of these apply then there's no reason to be buying commercial and one SHOULD be fabricating their own because it is challenging, interesting and there's something special about the kegerator that you build yourself.
