What's recommended for securing the CV Boots to driveshafts and where do I find them?

plastic Zip ties

Try the usual suspects.
linky

stainless steel cable ties,
screwfix do them for

£10 for 50, 200mm long.

http://www.screwfix.com/app/sfd/cat/pro.jsp?id=20645&ts=43152

--£10.99

I always use zip ties.....

I've always used plastic cable ties,

but I only recently discovered these nice s/s ties, I'm going to use them for securing exhaust heat wrap.! must better than twist wire..!

frost have just started selling these (and the tool for them)

http://www.frost.co.uk/item_Detail.asp?productID=9419&frostProductName=%20Boot%20Bands%20(2%20piece)&catID=37&frostCat=New%20Products &frostSubCat=&subCatID=

not as cheep as cable ties though