The h4150 can use with GPS but it won't be really smooth especially if you plan to use it heavily as 64MB of RAM on WM2003 is not quite enough for heavy usage. However you can cut down on RAM usage such as removing today screen programs & other applications that install into the main memory (RAM).

By the way, the more channel a GPS receiver has the better the reception signal. Furthermore, one need to consider the chipset of the GPS receiver too where a good one should be using the SiRF Star III chipset.

If you are a beginner & just using GPS for fun then a normal bluetooth GPS (put aside the chipset type) will do such as those from lelong, not necessarily need to go for the particular chipset (which might also costs more even if you managed to find one locally).

15MB of RAM left should be fine for GPS (considering most GPS mapping software required a minimum of 5MB of RAM available) but take note that amount will probably decrease over time especially for continuous usage. Besides, I also advise you to close all running applications in the background so you can achieve optimum performance.

Bear in mind that most of Peninsular Malaysia's GPS maps only cover major city areas. Even if there are maps for small cities, it won't be comprehensive.

Bluetooth GPS is the receiver itself.