This group, Cerebral Meltdown, has created a very similar project, and it is up and running. Great source to informatuin and feedback through the forum's users!

Similarities:

1. 4 kWatts on a tower with 2 axis of motion.

2. Microcontroller controlled, with an RTC tor time keeping.

Differences:

1. Uses variable speed stepmotors and drivers. I use 72 RPM synchronous motors.

2. The gearing is through multiple stages of chain sprockets, or a worm gearbox. I use a single stage modified worm.