Thanks for all the input, this is such a helpful and friendly community ! I haven't settled on how to pack the bike yet, I'm first going to try a LBS for a cardboard packing box and see how this measures up. The alternative will be to try a big poly bag of the CTC type thats been mentioned. I'm inclining to take along the mudguards and I have the winter months to mess around with different ways of packing- I think foam pipe lagging and Duck Tape are going to be involved as well.
Thanks for the suggestions about places to visit John. I'd like to cycle in the North, from Rhumpi, across the Nyika Plateau, down to the lake and along the shore heading south. i'm a bit apprehensive about some of the steep hills but my philosophy is if its too hard to cycle then get off, push and enjoy the scenery.
Its fun planning the trip, I'll post on progress.