Can the Slackware be customized to run fluxbox, and say apache and proftpd??
Definately. If you are going to be running apache, fluxbox, and proFTPd, I would recommend going with sXb Release 2 (~400MB download here
) since it is the latest Slackware 10.1 with the libraries you will need.
You would probably find yourself spending a lot of time getting the correct libraries on sXbmini. I would recommend finding the correct Slackware packages in .tgz format for your programs. Then running tgz2img after downloading them to your Xbox running sXb. After that script runs, you will have a .img file you can use which injects the program when you boot sXb. This way, when new sXb versions come out, you can just transfer your .img files and configuration files.
If you have any specific problems, don't hesitate to post them here or at the official sXb forums here
GOOD LUCK let us know how it goes.