Oak aging



So I've been really getting into beers that are aged in barrels
(especially Old Engine Oil Special Reserve Stout).

I'd love to find a good whiskey barrel to age my beers in. I usually
bottle condition. If I got a barrel, would I essentially use it as a
secondary fermenter before bottling and carbonating? Is it possible to
get just as good a flavor with oak chips soaked in whiskey?

Finally, do you all have any good sources for used whiskey barrels
that are a decent size, like 5 gallons?