Right now, gimp.
cc that, I use GIMP have been for years....
I would add a bit of noise to a duplicate layer, copy the layer again...(the original) desaturate the colors....and then mess with the "mode" and opacity....you don't need to do much, the blurring you did a'ready makes it look good....
experiment with the "modes" that is a great little tool(it is in your Layer stack window...... up top)
not sure how much time you have in GIMP.....any questions at all man, shoot em my way.
just thought of something....I actually use GIMP Painter.....its GIMP with a new Brush that will blend the colors very similar to the way it is done on a real canvas....might wanna check that out..if you are getting into it big time...if not dont worry about it.