As Colin has said I can fix you up with the drive shaft kits for the clicky noise if you require them
The noise that you are describing from the drive train could be nothing more than you just labouring the car and as you have confirmed, dropping a gear gets rid of the noise.
Worst case scenario could be a new clutch kit and possible flywheel.
The springs could be rattling about in the centre plate or the dual mass flywheel may be falling apart.
Either way I have all the parts available should you require them.
Axle Kits, Exedy Clutch Kits, OEM Dual Mass Flywheels, or Fidanza Lightened Aluminum Flywheels.
Hopefully you wont require any of the parts and a slight adaption to your driving methods may cure the issues.
Alex.