Can't answer your question directly, but something to consider with maemo-mapper is the speed of your connection and whether you want to have it automatically download maps. First, the maps are somewhat large compared to download speeds over some wireless networks. Second, you could easily use a large portion of your bandwidth cap on your plan if you have one just by downloading images. So, better bet might be to plan your route, download the maps along your route ahead of time, and turn off the auto-download feature. It's very easy to do that way, just takes a little planning ahead. As far as bluetooth GPS gooes, there's a thread on the forums talking about which models work, there are plenty that do, I personally have a Holux GPSSlim 236 that does a great job.

Sorry I can't answer the phone question directly.