In principle, you could use an SE/30 for this. However, a more modern pre-1998 Macintosh model with a built-in CD-ROM drive and an Ethernet card would be better. It would be an advantage if the computer is running System 7.5.3 or later. If the Performa 5200 that you found is cheap, I would not be too worried about any limitations when used mainly as an intermediate machine (of course, providing that the computer does not have the defects mentioned by Jeff). In order to make things easier, ensure that the computer that you buy has a working operating system from the beginning.
Please note that the downloadable free System 7.5.3 works on a Performa 5200 but not on a 5500.
System 7.5.3 or later means that it is easier to set up TCP/IP networking. Also, the system contains a PC Exchange control panel, allowing transfers on PC disks.
If StuffIt Expander is installed on the Performa, and if the proper CD-ROM extension and helper files are in the system folder, one can also transfer files on a CD-R (burn at a low speed in an ISO format). Just keep any compression (.sit) or encoding (.hqx or .bin) until on the Performa.
The highest supported OS is not always the best or most suitable OS. A newer OS often requires more RAM, and it can be slower.
Jan