Just my $0.02 worth, but I would stay away from SanDisk. I have had two bad cards from them (the only two I bought). One quit working after less than a week, the other was DOA. I heard that they fixed their quality control problems, but I have sworn them off. I have several Sandisk CF cards that have worked very well. You will need at least one 32M CF card for flashing ROMS. I would get one 32M or bigger and dedicate that one just for flashing (some flashes don't take if there are other files on the card). I would also buy the largest capacity CF and SD cards you can afford for program storage. I have an SD card that lives in my Z (it never comes out). I have programs, backups, and data on it. I have several CF memory cards that I swap in and out of the Z depending on what I want. I also use them to move data around to other devices (camera, various computers, etc). I have a NetGear CF Wireless network card. It is a requirement for me. I have heard of some people having problems with Netgear (physical failures), so I stopped reccommending this card. It has always worked for me without a single problem. I have a 10/100BaseT wired CF network card that has not been used in years (since I got the wireless card). Unless you have a specific need for one, I wouldn't get one (it is for sale though if you really want one ). I also have the camera card. I hardly ever use it. The quality sucks (my phone is slightly better). I used to use it a lot before I got a camera phone. I wouldn't reccommend it unless you can get a very good price (I paid $15, and that is about what it's worth) and have a definite need for one.
The first priorities (in my opinion) would be to
1.) get one small CF memory card (32M or bigger) for flashing only
2.) Get a large capacity SD card (I like Lexar) for installing programs, data, and backups in your Z.
3.) Get a large capacity CF card (again I like Lexar) for removable storage type items.
4.) Get a wireless CF network card (you will be amazed at the benefits ie internet just about anywhere).
5.) Get more CF memory cards.
Good luck and let me know if I can be of any help.