The first thing to mention is, be patient. Creating maps like the ones you mention takes hard work, and commitment. You have, however, already taken the most important step, which is joining CG and asking for help.

Regarding your latest version:
--you might have already planned to do this but I think you should remove the equator and tropic lines before posting a finished version.
--the text is very difficult to read. One thing you could try is making it off-white, with a dark grey stroke around it.
--the different elements of the map (borders, roads, cities, etc.) don't show up very well now. Try some alternative ways to show them (some possibilities: make roads an off-white colour, give borders an outer glow, put a diagonal parallel line pattern on top of the cities)
--in order to get closer to the map you like the most, make the land less saturated (browner/greyer and lighter), and make the water a lot lighter.
--once you've made a bit more progress with the steps above, some texturing will be necessary, I think (i.e. making the water faint in some areas, dark in others, saturated in one place, desaturated in another)

THW