i've ordered some lunapads and some spare liners. it sounds a great concept - just change the liner and keep the base (rather like the nappy and wrap idea!) - and it will limit the amount of CSP i need to take to work with me (with everything else that i need to lug around with me that sounds great!).
edited to say the best 2 part system Ive found is this http://hyenacart.com/AmazPadz/. I have some of hers and love them but Im not sure if she is selling at the moment. There might be some second hand even unused on the market if you advertised for them.