Before I get into the response to your specific questions I have a question. Are you really serious about trudging about with your laptop open in your hands to help you navigate on foot?
1. Look for receivers that have SirfStar III or MTK chipsets. You can usually find that information on the manufacturer's web site. If there are additional modern chipsets perhaps someone can add to that list.
2. You are somewhat on your own here. If you want the broadest possible usability, look for conformance to NMEA 0183 for the data output. Look for the ability to control how the output appears to the nav software on the PC (eg. USB direct versus virtual COM port, control over which COM port and the port speeds).
Of just make it easy on yourself. Forget about the GPS receiver until after you settle on the software and maps. Then just buy a receiver that will work with your chosen software.
And be happy with the awareness that GPSGate can interface darn near any GPS receiver with any nav software. And it's really cheap.
3. You need to look for the availability of maps before you even begin to think about which nav software. Check out
Malsingmaps.com to see what maps and software are recommended for that part of the world. It is a very well-used site and contains a wealth of information about that part of the world.
There are two general approaches to navigation in that part of the world. Either get a Garmin product so you can add Garmin compatible maps for all those places that Garmin doesn't have coverage you can buy from them. Or get something like OziExplorer which gives you the possibility to roll your own map coverage but has a pretty steep and tall learning curve (the process of getting maps into it and working together for the desired coverage).
Look around on Malsingmaps and if you still have questions that you can't get answered there, toss them in here and we'll see if we can help. If you do, please make sure the subject of your post includes that you are looking for help in navigating around that part of the world so you will attract the right segment of our members to look at it.
4. Yes.
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