Help Finding The Right Heightmapping Software for A Project

[LordIndy]

Played with Wilbur a little bit, but not as much as expected. Begining to think its not anymore time saving than manually creating heightmaps.

Thanks Redrobes it's been really helpful so far; so if I'm reading this correctly its something like:
-> hand draw the continental outlines
-> Scan and reduce to two colors black/white
-> color fill oceans black and continents white
-> do contour steps from highest peak to lowest ocean trench
-> muck it up with some noise and blur
-> Multiply original overtop
-> Do river work
-> Slight blur
-> copy/paste some real world DEM if wanted somewhere in those steps
-> then run it through a program(s) [Global Mapper, World Machine] do the detailing based on some sort of erosion, biome, etc options?
SAMPLE_TEST.png

Sample image steps:
255 / 8 = 31.875
~ 32 per step
1= 255,255,255 Highest Peak
2= 223,223,223 Land
3= 191,191,191 Land
4= 159,159,159 Land
5= 127,127,127 Land meeting Waterlevel
6= 95,95,95 Skip
7= 63,63,63 Extent of continental shelf
8= 31,31,31 Open Ocean
9= 0,0,0 Lowest Trench

Gaussian Blur of 30H&30V
Multiply Original over current
Gaussian Blur of 1H&1V

Just want to make sure I'm understanding it correctly; whipped up a quick sample.

It sounds a lot like my initial workflow, but I wasn't sure it would be very fast, nor what/if any programs would complete the finishing details.
What programs do you use after creating the basic height map?
Am I going to have to create like 256 steps/shades manually, or should I only do like ~20 and let the program(s) fill in the gaps?

[EDIT] I'll definitely look into/demo Global Mapper; spending money is definitely an option in this case.