What is best for you depends on what you feel is the restriction of your current kit. If you have no problem with AF, 6mpix, high ISO, operation speed, etc of the K100d, I dont see a need to upgrade body. If you have problem with high ISO, get K-x, if you need WR and faster AF, get K-7.
If you dont have any problem with K100d, but just feels the need to upgrade, I'd recommend 16-45 + 10-17 as it would upgrade your current kit lens, and the 10-17 would open up lots of possibilities
I see you dont have a fast 50 yet? You know that you dont have to bring all your lenses when shooting, right? just have what you feel like using for the day...