I believe that you will see a benefit in the cup with an upgrade and if you do it well this time, you will have a grinder for life- which will be perfectly matched to a new machine if/when you choose to upgrade.
You are looking in the right direction with Compak, Macap or Mazzer. All are terrific grinders.
Each machine/grinder is a box of compromises and its a matter of finding the best match for your requirements.
Please feel free to give me a buzz if you wish and Ill be happy to discuss pros and cons with you to help ensure that you purchase the correct grinder for your requirements.