Hi, a couple of suggestions. Check this thread New Linear Z - Rev 2 - Now updated for easy tram adjustment and this one Looking at bringing a new Z axis to market
You will see the new Z I built following MrBeavers design in the first link. In the second you will see that MrBeaver is now commercializing his design. So, build or buy, your choice.
You may want to get a bit more experience with your stock machine before you start changing things up.