Not knowing specifically what you have changed/upgraded, I would suggest you take the time to go thru the thread about mods/upgrades here on CNCZone. here is a link to the thread
You have probably done most of the changes already but the details are in the threads. I went thru it with a notepad and jotted down the things I wanted to do. I actually purchased an assembled kit and then went backwards to see what mods were needed or I wanted. Didn't take that much time. Probably the biggest is the possible upgrade to different Acme screws to help reduce the rpm and 'whip' on the X axis. The Joe's 2006 will work well as originally designed and the mods/upgrades can all be retro fitted in the future if needed.