A lot of the professional artist on Deviant art that I know use Photoshop and if it is brushes there are websites that can give you different types of brushes for free! I personally like Photoshop over Sai because its a lot easier for me to use from finding my tools and using the layers, plus there are more tools that can help with the special effects that you are looking for. Sai is a good program too because the various brushes it has and the smoothness of the lines and probably more (I'm still practicing on that program). But, if I had to choose I'd go with Photoshop.

All those artist are great I admit, but comparing yourself to them is just going to bum you out and do nothing for you. In order to get better, instead look at these guys are inspiration. Examine their art thoroughly to see how they shade or color, watch them live stream draw if they have one, or better yet watch a lot of videos that can help you with Photoshop in the areas you want to get better at. If you see an artist that you like that does something you want to do, then try to experiment and use a drawing as a reference for yourself.

http://www.youtube.com/watch?v=Y6ggxyPAqts - If you need an example of a Photoshop user. With this artist he used a lot of color blending so perhaps experimenting on what colors blend with what might help.

http://www.youtube.com/watch?v=cKAIfODX31o - Maybe used to watch the process to help with shade and blend?

And...that's I have to offer. o _ o
...Sorry if I wrote too much.

Thanks so much dude for your help

I would like see them in live stream but they do it very occasionally...

You're welcome and I hope it helps <:3

Oh and here is the website incase you need for brushes -

http://myphotoshopbrushes.com/brushes/

http://www.brusheezy.com/brushes

*pops you*

really x)

http://ctrlpaint.com/library/

thanks for this link