My favorite wireless keyboard/mouse for HTPC is the Logitech K400r. It's not bluetooth, but that's a positive in my book. Bluetooth has a lot of drawbacks when it comes to HTPCs. It can't wake, it doesn't work before the OS boots, and it's expensive and power hungry compared to RF ones. No thanks.
However, if you do need it to be bluetooth, then the Logitech MX 5500 Revolution Bluetooth Mouse & Keyboard is probably unbeatable. The mouse design is just plain fabulous! I haven’t followed the price in a very long time, but it used to get discounted (and/or with rebate) occasionally.
I would suggest the Logitech DiNovo Mini. This is good if you want something small. It's can also work as a navigation like you would see on a regular remote with a flip of a switch. It's not without flaws. It's not good if you have to do a lot work within the OS. But great for keying in URLs, mouse clicks, and so forth.
In my experience, it woks well overall. The problems I've encounter were my "D" key doesn't always register. When the batter gets low, it randomly looses connection to the HTPC. Usually opening and closing the lid twice while waiting about 5 secs seems to get a reconnect. I've been using mine for going on three years. For me, I didn't want a full size keyboard or mouse. I only need it those once a year or so, so I drag out my spares in those times.
As for waking, that is not necessarily true. I haven't explored it in WIndows 7 on how, but my HTPC power button is easy reach. When I was using OSX for my HTPC, I was able to wake the HTPC with the DiNovo Mini. I figure there is a way in Windows as well.
There are other similar alternatives. Some people like the Rii, I think that's what it was called. It's a lot cheaper than the DiNovo Mini.