Hey man... some advice...
I use Nivea Skin Creme... keeps my hands nice and moist... just rub your hands on a (clean) towel before you start fiddling with the cards and they won't get oily!
At least mine never have

And if it's JUST for dry hands... apparently Avon do a cracking moisturiser, although I'm not sure how clean that would leave your hands. Might end up a bit greasy.
Errr... card guards are not my forte, but I understand the ones from magictricks.co.uk are pretty good. Not heard any complaints about them certainly.
And number 3... Jay Sankey's No Card Tricks has a beautiful version of the $100 Bill Switch in it.
The one I made a video of, was kinda just showing off. there wasn't really any magical application behind it (except that it fitted in with the story nicely...) but the one Sankey teaches is beautifully magical.
There's also another good "Weird and Weirder" trick he teaches on the same DVD using the Bill Switch too.
Great trick all in all and Sankey is great at teaching it.
I picked it up (to the level of my video) in about 3 hours... (takes some practice, but well worth it)
Hope that's of some help!
You wont find much better anywhere and it's nothing - a rigmarole with a few bits of paper and lots of spiel. That is Mentalism
Tony Corinda