Share your experience!
I have a kd55x8509c.
I purchased a bog standard wireless keyboard/mouse combo,connected receiver to usb 1 and all works perfectly.
i can use opera browser and keyboard functions also work on Bravia main screen.
I use Google Chrome that I sideloaded use Chainfires Sideload Luncher to load it and my keyboard and mouse works like on other devices.
kd49x8039c
Another good one is the Logitech K400 combo.
I use this one which includes a touchpad, obtained on Ebay for £12 or so. It is bluetooth and connects directly to the TV bluetooth. KD43x8307. Works okay, controls media as well for the most part. Keys are a little compact for serious typing but okay for inputing URLs and such, has a back light which is handy.
I purchased this wireless mini keyboard and works great with my KD-55XD8599. Plug the wireless dongle into one of the USB slots and instantly connects:
Rii i8s 2.4GHz RF Portable Mini Wireless Keyboard with Multifinger Touchpad Mouse
Edited link.