There isn't a paid or free version of Photoshop for Linux you may get some success running it under WINE but an alternative would be to make GIMP look like Photoshop which is possible if your running version 2.8+. First download the latest GIMP offering 2.8+, enter Terminal and add this PPA, update your repository cache and then install GIMP.

sudo add-apt-repository ppa:otto-kesselgulasch/gimp

sudo apt-get update

sudo apt-get install gimp

Now you need to download the icon set. Here's the download link for the icon set: GIMP toolbox like Photoshop - Gnome-look.org

As Photoshop has icons In the Tool Panel that can change if you hold them down, you'll have to approximate the layout to your taste in Gimp. Here's my Layout that I chose:

The '.gimp-2.8' directory is located in your Home folder, but it's hidden, so just press Ctrl+H to toggle the hidden folders.

You'll place the new icon theme in the folder titled "themes", and if you wish you can also copy the other files that came with the set to alter the shortcuts etc. (they will overwrite the old ones, so back them up if you need to).

Changing the UI:

1. If you prefer Single-Window mode, select it now in the menu "Windows".




2. To get the Tool Palette narrower you'll need to drag the Brushes away from the panel. If you prefer a minimal layout and really only use the Layer and History Palette, but feel free to add/remove what you like. This is one of the big annoyances with Gimp's default layout – there's just too much on show at once and those brushes take up way too much space!




3. The Canvas colour also needs to be adjusted as it's not dark gray, to change this, head into 'Preferences' under the "Edit" menu and change Appearance →Custom padding colour and also 'Custom Padding Mode' Having a dark canvas is easier on the eyes after you've been playing with GIMP for several hours. Plus it makes it less distracting when working with photos or images.




4. Play around with other preferences as you wish Preferences→Toolbox→Tool Configuration to suit.




5. Increased the Layer Thumbnail size in here if you wish.

And that's it GIMP should now look more like Photoshop and be a little more user friendly for those unfamiliar with GIMP.