MineZ is quite difficult, and there are some mods that can be used without being illegal:

That mods are:

Gives a minimap in one of the 4 corners of the screen. Also you can put waypoints with the "c"

Improves the fps a 200% (Very good for older computers)

Let you classify your inventory.

If you are a noob installing mods here it is a download to an archive with all this mods already installed: