I recently just did the same thing on Linux Mint 10 and Gnome.
I also installed the mint-artwork package but in the end I had to do all the configuring manually - which wasnt that hard.
the first thing I replaced was the pretty ugly (imho) panel or taskbar or whatever its called from the original fluxbox with the same used in LM9 Fluxbox RC -
after you installed that one you will want to remove the original one in
~./.fluxbox/init - just remove the system tray in the
session.screen0.toolbar.tools line.
and also set
session.screen0.toolbar.visible to
false.
after that you should also edit the
~./.fluxbox/startup file and add tint2.
you might also want to add some other kde apps you want load in that startup ( I load nm-applet and some other gnome stuff like gnome-keyring and gnome-settings so I can use my GTK theme and connect my existing wifi connections I already set up in gnome. dont know what kde uses though.
the style that the LM9 Fluxbox RC uses is called shiki - i think you can download it on
http://www.linuxmint-art.org. just unpack it and move/copy those files to either
/etc/fluxbox/styles (global theme for every user -> need root access to do that!) or
~./.fluxbox/styles (local - just for your user).
I havent checked out the Fluxbox Menu used in the Fluxbox RC but since you can easily configure it yourself to your needs its just better you just quickly write your own menu - that comes in handy if you plan on using some kde apps in fluxbox too. Its all documented pretty good on the fluxbox site and it is pretty simple.
you can manually change the menu by editing the
~./.fluxbox/menu file.
another thing - if you dont find the app you need to do whatever you need to do (for example editing those 3 config files) you can always start them with ALT+F2.
Hope that helps!