Hey mazmazmaz1,
The company stoped producing those two models.. it is very hard to find.. I heard that some other company started to do the F40 not sure what is it called.. maybe someone will tell you latter..
If you seriously want the F40 and F50 you can always try ebay.
Just few I found on ebay.com
F40
http://cgi.ebay.com/ws/eBayISAPI.dll...908044501&rd=1
http://cgi.ebay.com/ws/eBayISAPI.dll...907250884&rd=1
F50
http://cgi.ebay.com/ws/eBayISAPI.dll...908241458&rd=1
http://cgi.ebay.com/ws/eBayISAPI.dll...906912693&rd=1
Just in case you want something very speacil.. F50 in chrome paint
very expensive but looks very nice..
http://cgi.ebay.com/ws/eBayISAPI.dll...907451186&rd=1
by the way welcome to the fourm this is the first time I notice you around.