As of now I would have to strongly urge you to go with the ir extender you mentioned in your post.
I have been using it on my PALM 3 and it works great.
This type of extender really brings out that the most in a lcd screen remote such as the PALM,in that allows you to control your equipment without aiming the remote.
Trying to aim a remote without the tactile feel on hard buttons is a real pain.
If the people that made the ir booster for the Palm were smart they would develope the the same type of device that plugs into the Palm ,but have it send out an RF signal that could be converted back to a IR signal.
Another benefit of using this gizmo is you can have smaller(more) buttons per screen beause you will using the remote the way a PDA is supposed to be used, directly in front of you,not trying to aim it at the device you are trying to control.
As of now all other options leave something to be desired.