Heated gear will change your life!
I've had a couple sets of the wrap-over grip warmers. They work damn good. My first pair lasted 3 winters before one of the wires broke. I'm still on my second pair. I think this will be my 3rd winter with them (if they get any use).
I just put the permanently mounted under-grip warmers on my TTR250. So far they work awesome as well. Both the wrap-overs and stick-unders will heat your grips up to the temp of a fresh hot cup of coffee.
Now with the heated clothing, DIY is the way to go!! This is the GRM board after all! The store bought stuff seems like such a rip-off once you see how easy it is to make your own. Try here:
http://home.mebtel.net/~rbutterfield/Heat.html
or here
http://www.instructables.com/id/DIY-heated-clothing/
Basically, you get a long piece of 30awg Teflon-coated wire and connect it to the battery terminals. The resistance of the thin wire makes it really hot. The teflon coating won't melt. Get some switches, fuse holders, and battery connectors and you're done. You use a big sewing needle to thread the wire into whatever clothing you'd like.
I've done this twice. My first was a fleece vest. I slapped it together quickly as a proof of concept, but it worked so well I've been using it ever since. I think 4 winters now. My second, I wired up the removeable lining in my Joe Rocket touring jacket.
The vest works GREAT as it is tight on me and can be worn under your hoodie or jacket or whatever. The closer the heating element is to your body, the better. Any wind or drafts that get between you and the heating elements and the heat is wisked away. Which is why my wired up liner isn't as good. The jacket is already a little big on me and the liner doesn't sit real tight against my body. This makes things a bit warmer, but doesn't make me all WARM and cozy like the tight fitting fleece.
The only other thing to keep in mind is to wire up your clothing so that no individual wire is touching any exposed skin. They get HOT and sitting against your skin, it will burn you after a while.
If you pinch the fabric of a store-bought heated vest, you will feel thin wire inside. I'm sure its the same 30 gage teflon coated wire as I used. And I got 100ft of it for $8 or so, enough to make 3 jackets...
As far as Hippo Hands, I've been interested in trying them. My local scooter shop sells something similar:
Scootr Logic Mitts
http://mpgmotors.com/catalog/product_info.php?products_id=15755