Not necessarily. I ordered the Recovery DVD, but that was because I wanted one. It is possible to do what you're intending without need of a floppy. The solution is a bit technical, but you seem like you do this stuff well. I did this for my workstation PC (which has a SATA boot drive) and it worked flawlessly.
What you want to do is called slipstreaming
. Basically what you're doing is taking a standard Windows XP install CD, adding the drivers that you want (like for a SATA controller), and reburning the CD. Now you have an installation CD that has the drivers you need built in, and will load them at the proper time in the installation sequence.
If you want, you can even "slipstream in" things like SP2, IE7, WMP10, and other apps. The install CD I built for my office PC has the drivers for all components (MOBO, graphics card, on board sound, LAN, etc.), SP2, various hotfixes, and other things slipstreamed in so when I have to do a reload, it loads it all at install time. Less stuff I have to download after install is complete.
The guide I used is Paul Thurrott's guide
. It was a lifesaver and explained the process very well. That will tell you how to slipstream in the SP. To get the drivers integrated, you'll need to use a tool like nLite
. If you have a second PC to do all this on, give it a try. The most it could cost you is a blank CD or two.
Let me know if you have any questions on that one. Like I said, I did it for my other PC, and could have done it for the z555, but I wanted the Recovery DVD anyway. Good luck!