Yeah, go for it.
I was asked to audtion for a similar band late last year, doing 2 sets 50's/60's RnR, 1 set Elvis, as the singer does solo Elvis tribute gigs..
As some have said, remembering all the stops is the hardest part.
http://www.rattledmusic.com/
The biggest difference I have noticed is when you gig with a classic rock pub band, every gig you have to prove yourselves. It's rare for the punters to be really enjoying it before half way through the second set.
With the RnR, the girls are usually up from the 1st number. They are there to enjoy themselves rather than be kinda critically cool.
Got some good gigs out of it as well, such as Monaco Ballroom, Cavern and we're at Glasgow's Grand Ole Opry on July 23rd.
The one thing I detest (it spoils it for me) is a different "uniform" for all three sets.
Enjoy