So I got a few PMs about this- sorry life has been busy and I haven't logged in this forum for like a year. Here's the full story on the ramp..
So I ended up getting carpet option #2 - it was from a different store and the carpet was a marine grade (like for boats etc.) and was brown in color. Same closed medium length loop. I wanted to build a really legit ramp so for whatever reason I though it'd be better to build it with a progressive angle like a quarter pipe instead of a flat ramp.
So we built this thing all legit and dumped a ton of money into it. When we were done the quarter pipe style was a really really bad idea - the it caused the board to flex waaay too much and really put heavy pressure on the front/rear tips of the board. The tips then dug into the carpet and would essentially lock you into whatever direction you started in - it was next to impossible to steer or move your board once it stated moving.
Here's a video, in reverse for whatever reason, of us building the ramp:
Snowboard Ramp in reverse time lapse - YouTube
So you can see it's waaaay too steep and the quarter pipe thing was a wicked bad idea.
So I did some work to the ramp and tried to lessen the steepness of the curve... but after all this it still didn't work - just couldn't steer the board once it began sliding. I kept falling off the ramp and it was getting to be this huge source of fail.. I spent too much money, it never worked, it took a long time, and it really hurts when you fall off this thing. Every video I see on YouTube is of some 12 year old kid using a free tarp he found and stacking some wood pallets he stole from behind a grocery store and put a ramp together in 20 min and has hours of fun riding it.
So after spending more time, and more money I modify the ramp. I'm convinced this time it will work - so I get up early before work - get my wife and son out of bed so they can watch dad's epic jib session on the "new and safe" ramp.. this is what happened:
Snowbard ramp fail - YouTube
So my kid (nick name "Pico Fish") thought I died.. yet again, on daddy's wicked evil horrible ramp..
Out of sheer frustration I completely disassembled the ramp so the reminder of my epic fail would not be in my backyard reminding me each day.
All that being said - I think the carpet WOULD work out, but I'd probably go with even a shorter loop like option #1 above - and I'd just start really easy - find a grass hill somewhere and cover that carpet with soap and water.. try it out before building. If you do build, don't put a contour in the ramp!