You'll find a little of both (some tab but mostly just chords)
Most of them are simple enough that once you figure out the key you can improvise pretty easily. I think you'll find some tab for Big House - which seems to always be a favorite of kids and adults.Try ultimate-guitar.com, and theres always buying the copyrighted music digitally on-line (sheetmusicdirect.com, sunhawk, etc.)
Some of these tunes may sound a bit laid back but there's no reason you can't wind em up a bit.
I hope you enjoy.