I would do my best to keep it real, don't try and use drum machines and electric guitars, with a solo act... that just gets cheesy fast!
Play it acoustic and keep it real, Elvis is a great show, I have to admit I wanna play his stuff too!
Keep it real, talk to a starbucks near your house and see if yo can get a night a week, call up venues direct and find out just who at the place you wanna play does the booking and pander to them instead of passing out costly press packs that the booking person may never even see.
Something that could really boost your numbers if the venue can support it is to close the show with Love Me Tender, but pick out a random female from the audience and give her a rose and sing the song to her... I dunno why but even a cheep gas station rose and that voice and song will create enough stir that suddenly you will have a LOT of women showing up at your veneu to see "Elvis" and if a lot of girls start showing up.... So will a lot of guys to come hit on the girls!
I used to a know a cover band in Cincinnati that would take a part of the show and pick out the best dressed couple in the room, and give them a bottle of wine and a dozen roses, suddenly a rather casual bar gig turned into a pretty classy gig for them, and the choices started getting a whole lot better for winners of the contest, course it was cheep wine and cheep roses but IT WORKED!
My show I give out a copy of my CD, bring out a guest musician to play 10 minutes for me, and almost every time they bring some people with them to hear them play, but most of the time they stick around to hear me too!
Gigs have to have something to draw people and keep them coming back, if you play the same old Elvis gig every night it is gonna get dull, but you should be able to get something going if your show is unique enough.