We've done kegs for a few parties, with people approaching us informally.
The problem isn't so much with the kegs but, as mentioned above, it's the paraphernalia to get the beer from keg to glass, i.e. the serving gas, the chiller and tap etc.
If you want to drop me an e-mail at <!-- e --><a href="This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it. with what you had in mind I might be able to advise.