Amazon offers the Logitech K400r Wireless Touch Keyboard with Built-in Multi-Touch Touchpad on sale for $29.99 with free shipping on orders over $35 or free 2-day shipping with Amazon Prime . Control your TV-connected laptop/HTCP from the couch with 33 feet wireless range. You save 25% off the retail list price. That's the lowest price we could find currently.

This keyboard would work great with a HTCP. Features built-in touchpad, plug-and-play, works on 2.4 GHz wireless with up to 33 feet away, media hot keys and more.