Zauruman,
The brand sandisk is available in about every shop around me at reasonable prices, so perhaps easiest to stick with sandisk then? But what about the rumour they delivered malfunctioning cards? (Apparently they corrected that?).
For me, the SD card is meant to function as "permanent" storage (so the SD card will be used to install programs and that card will stay in the Z at all times). Therefore I think this should be at least 512Mb, 1Gb prefered...
The CF card, on the other hand, will be used as removable storage, like a diskette. The CF slot will have the Wifi card when needed, otherwise a CF memory Card with games (mame, ScummVM), mp3, movies or data. Here it could be handy to have several 128Mb cards, but for Lucas Arts adventures that are "talkies" (or the Monkey Island CD version) it would be handier to have a 1Gb card so it will be able to contain the whole Lucas Arts collection unless I restrict myself to the non talkie versions
Offtopic:
In the end the Z is an expensive toy
I got mine (SL-5500) for only 290 euros (including leather case, extra screen protectors and a 128Mb CF card) but what's a Z without connecting it wirelessly to your LAN? (and showing off it's power by wirelessly receiving a live stream from a TV card on your LAN).
What's the Z without at least an extra CF and SD card? I got a laptop with a dead battery and I don't want my Z ending up the same way, depending on a wall outlet converting it into a not-so-portable device, so I bought a Socket Mobile Power Pack as an external battery. With all accessories, including Card Reader, it's an expensive toy but boy, what a nice toy
I'm a bit disappointed with the CPU power of the SL-5500 (I wonder how long it will take before the SL-5500 can't keep up with software demands anymore), but then again, it's my first PDA, so I can't complain. I hope a lot of newer models will appear quickly one after the other (already happened: SL-5600, SL-6000, C series, SL-C3000) and prices will drop quickly.
And then I'll hope all accessories & memory will still be compatible in the future, but we'll see about that.
Long live King Z.