Add-on computer options for Celestron C8 Deluxe

I have a Celestron C8 Deluxe. It doesn't have any kind of digital setting
circles or "go-to" computer. As far as I understand, there are three
possibilties if you want a computerized telescope:

1) Install a full goto computer system that has a hand unit with a star
catalog, and can directly point the telescope.
2) Install a hand unit with a star catalog and a set of digital setting
circles.
3) Install digital setting circles that interface with a PC. The PC has
software with a star catalog and is able to read the output of the setting
circles.

I've been to JMI's site and they have a set of digital setting circles for
about $400 that can be read from a laptop computer with astronomy software
installed. Does anyone know of any other digital setting circles that could
do this, or is there another solution that would be around $400?

Neal