i think Photoshop is a creat software to use alongside general photographing. Yes there is a little learning curve involved, but there are tons of video tutorial (both free and paid) that are great in getting you up to speed. Photoshop Elements is the basic version of the program (and less cost expensive), and such sites as VTC.com and Lynda.com have training CD's that are always worthwhile.

Some say get it right first time via camera. Yinka Oyelese page you linked looks pretty impressive and cant help but to think there was some Photoshop done in this photos (even if it's just Brightness/contrast & Levels).

I can always post a small tutorial up on here if needed to walk you through how to create a Gradual Neutral Density look on your photos. It's not as hard as you may think.