..check out Little Church of the West.
http://www.littlechurchlv.com
Basically across from the Mandalay Bay Casino (on the strip) and this church oozes history. Very calm and quaint. I have been to dozens of wedding there over the years, including my godfather's (back in the 1960's when it was at the Frontier)....LOVE this place! I don't believe they do "Elvis weddings", but it is very romantic and memorable.
Also, it's sorta close to the South Point, so all the chippers can "crash" your wedding...oh yeah, that'll make it memorable .
Darrell and I will even gladly volunteer to play "Cousin Eddie" at your wedding....he can pop a beer and I'll wail loudly (just kidding)!
Good luck in your decision.