So I could not find a cheap enough slide to hold $500 without being over $400. I decided to build mine and it came in at a total of $150 and a full days worth of work.
Here is the parts list:
$30 48 skate bearings
$34 24ft unistrut (superstrut)
$15 half sheet 3/4 plywood
$30 steel angle (2 1/4 x 2 1/4 X 1/4 thick) 24' this is 6 cuts at 48"
$15 aluminum sheeting (not required)
$10 rustoleum spray paint
$10 nuts / bolts / washers
$8 steel rod 5/8" x8'
It's built and the generator is mounted. I also added shock mounted feet to the generator home built from a double stack of non skid furniture rubber feet with fender washers between them. Works perfect to raise generator about 3/4" from the mounting board..
The flashing was placed all around the air vent opening on the mounting board and in the bay floor for the down-vent...