There are some pretty good mods around. I'd recommend OLC's OLC Gold MkIId. Its an excellent mod that also allows you to install the Longer Repair Times mod. In the end you have a demanding and fair realism level. Whats bad with OLC' mod is that the GUI and the environment are inseparable. There is a reason for that but if you don't want/like the environment (i doubt that) you can download his only-GUI version OLC GUI 1.2.7.
Another good choice would be makman's GUI or Mikhayl's GUI. Makman combined elements from both OLC's combimod and Mikhayl's own independent fine work.
Bottom line is that you have many choices so download, try, practise, ask around. Oh, and don't forget makman's TMT v2 mod.