Hi Sean.
I made one for our 65lb lab mix out of an aluminum ramp.
All I did was reinforce it with some 2x on the back where the horizontal slats were.
I put a strip of 1/4" plywood that fit perfectly into the channel on top. Then I put indoor/ outdoor carpet over the wood.
It was very lightweight, and long enough to make a nice gradual incline/ decline. She used it for the DP, truck , and car.
Got the ramp at Harbor Freight. It was nice because it had the little feet to keep it from slipping.
Took me maybe an hour to modify. Good luck.
Cheryl