The jigsaw mats that I've seen are for floor protection, not for people protection. They're a cheap temporary way of protecting floors in high traffic area -- they've got good scuff protection but no padding to speak of. Maybe you're speaking of a different type.
A $5 bokken is probably an expensive piece of firewood, but a much more expensive bokken is not necessarily any better -- there's a lot of crap weapons out there being sold to the wanker market. White oak is my preferred material -- I have a white oak bokken that I have had since...err....about 1992, I think. Some folks like exotic woods, but I'd stick to white oak and not pay a premium price for something that may be just a vanity piece, or whose difference from another wood is going to be too subtle for you to appreciate. Get a basic bokken, avoid anything stylized.
As for where to buy it, you might ask your sensei where he/she gets bokken. If that doesn't lead you anywhere, I'd say stay away from any website with "combat", "karate", "blackbelt" etc. in its site name. I haven't had any dealings with Bugei (http://www.bugei.com/category_23.htm
) but they seem to be on the up and up. Bujin, for some reason, seems to only have hickory and "Brazilian cherry" (yay exotic hardwoods, let's kill that rainforest!).