desktop vs. server?

[Joshua Solomin]

I'm about to try converting a spare computer of mine to Ubuntu (my
first real foray into administering my own Linux system).  I'd love to
get a chance to play with a good desktop GUI, to see if it would work
well enough for my purposes to fully convert over to Linux from
Windows.  However, I also know that I'll definitely want to use it as
a Samba file server, and possibly also web server/application
server/mysql.  So I'm waffling between installing desktop vs.
installing server.  Any advice -- would it be easier to enable
desktop-style features on a server install, or to add the server
utilities I need onto a desktop install?

thanks much,
Joshua