Can someone please assist with plans or ideas to fabricate a hitch for my Dragstar?

Not so good on the plans, although I could have a go at drawing... But I can do ideas easy enough.

Dunno what the SA laws are, but in the UK I believe bikes are limited to trailers no longer than 1m...

Try putting a couple of spars on the back end of the frame, at the bottom. Then have them chamfer in behind the rear wheel, to form a point. To this point affix a universal joint, so you can turn it up down left and right (pitch and yaw), but not roll. To the back of this, add a monowheeled trailer frame. If you need further support, a pair of additional spars reaching up toward the top of the frame should do it.

You should be able to lug 3-4 kegs of beer on that easy enough - You'll look awesome turning up at the next braai!!

Also, run a few Googles for ideas:

http://www.mono-trail.co.uk/

http://www.robertawhite.com/piggybacker.htm

http://www.hondarebelforum.com/f12/towing-ball-9976.html

http://www.svrider.com/forum/showthread.php?t=128943

http://www.customcruiserchrome.com/hitches