Although i have a wireless keyboard and a trackpad-equiped remote, i use this for
my HTPC:
"Rii 2.4ghz RF mini-keyboard". Also sold under 'Magic-Touch' and 'Pro-mini' brands About 30 bucks total, shipping across border. it's about 2.5 x 6 inches. About as long as my girly hands. Far easier than handling a full KB+ mouse, as it's remote-sized. THough If you do a lot of typing, it's not ideal, obviously.
RF connects instantly and works in BIOS . Is driver-less adn comes with a receiver. Charge time is tiny, battery life is amazing. I charge it about once a month but use it every day (takes about 20-30 minutes to charge, and you can use whiel charging.) Trakpad is good, but it only has one Shift key and no F9-F12 keys. Though There is a 2nd generation that DOES have 2 shitf and all Function keys.
I also have the Bluetooth version, but it's finicky about connecting, has less range, and does not work outside of an OS.
I got them from Amazon.