Depends how big the first level is. If you have a big 1st level then it shouldn't be a problem but if its just a 7.5 sq ft cage then I would reccommend building stairs, not a ramp. Look at some pictures of peoples ideas; Get creative with it.
How big a cage do you have now? If you already have minimal space, I wouldn't bother with the second level. When you add a ramp or stairs, it makes it much harder for your piggers to run around without bumping into things.
That's what I was looking at when I started designing the cage I'm building. I've since decided to not add the 2nd level right now. The L lets you still have lots of light in the first level though. Have fun building!