I just checked and I bought the Liftmaster 3800 two pack. I bought these 5 years ago for $577 for the pair. I don't know what the difference is but the 8500 2 pack costs $577. I just realized the link below is the same company I bought my openers from back in 2012.
https://www.opendoorremote.com/8500-2-pack-liftmaster-elite-series-garage-door-opener/
And why the raised rails? Are you wanting to be able to open the door with the car on the lift?