Most Polite Apps for Window Managers?

[Ed Sutherland]

I'm considering moving from one of the giant desktop environments 
(Gnome) to a svelter window manager (blackbox or windowmaker.) I 
understand some apps require only the gnome or kde toolkits, while 
others require the whole kit-and-kaboodle to operate. I'm wondering if 
these app categories can politely run in a window manager (that is, 
using just the gnome toolkit.)

E-mail (Thunderbird)
Web (Firefox)
Office (OpenOffice)
Contacts (Rubrica)
Thanks.

Ed