The single speed equivalent of the Dewalt 611 is the Porter Cable 450 which may be a better choice. 16,000rpm is too fast for cutting plastics so you will need an external speed controller. Typically that will require modifying the router to disable the variable speed control circuit and disabling any 'soft-start' feature. For more info look over this thread: http://www.cnczone.com/forums/want-t...-software.html
You will probably want to order your zenbot 4848, spindle mount, G540 4-axis control box & Mach 3 ...all from Zenbotcnc. If you go with a Porter Cable router, check with Shaun/Zenbotcnc to get the correct mount.
Assuming your PC is adequate in terms of processor speed, video resolution, & IO, you can use the tool paths generated by Aspire (or VCarve-Pro, etc.) to run the job within Mach3 on your PC once it that has been properly configured to work with the Gecko G540 and your Zenbot. Check the discussion thread on "Mach3 Configuration" at the Zenbotcnc forum for more info. See: Mach3 Config
HTH.
--Rich