For the Palm I would use TomTom. The latest version says it only works with Treo but I have a Palm Zire 72 and it works perfect. I think you should be ok with your two units also but I would do some searches. You should have no problem hooking your GPS to the palm or BB. I have a 8320 Curve and I can use the GPS with either, but NOT at the same time.

For the BB I think turn-by-turn is lacking. Once you use TomTom you can never use anything else.