Its best to avoid levels because hedgehogs are excellent climbers! well but only going up, they have poor eyesight( as what ive read) so they trip easily so they may fall. But asked between a ramp or tube? Ill go with the tube because its much safer cuz he/she cant fall off the side. If you can find the flexible ones they could be much cheaper and easier to use though! http://www.petsathome.com/shop/guine...glesafe-106365
if it cant support your hedgie support the tube with things like cardstock.
is that persplex thing like corrogated pastic? if so then just score the plastic then bend and secure on the OUTSIDE