Optimal Apache configuration for serving large files?

Hello,

I am currently preparing a webserver - I have done that several times
before, for the often found scenario where some html files, some images
and some scripts shall be served under several virtual domains; the
scenario that apache is best suited for, I guess.

But this time it's a whole new scenario, and maybe someone faced that
before and can give me some advice where I should deviate from the
configuration for the default scenario.

What the server is supposed to do is serving large files that users will
download, e.g. Zip files etc.

I know that probably FTP would be a better service for that, but we need
a php script on that server.

What I have already done to optimize the server is that I build a slim
kernel, compiled Apache 2.0.47 only with what I really really needed,
same goes for PHP 4.3.2:

Apache:
../configure --prefix=/usr/local/apache/2.0.47 --datadir=/var/wwwroot
--disable-access --disable-auth --disable-charset-lite --disable-include
--disable-log-config --disable-status --disable-autoindex --disable-asis
--disable-cgid --disable-cgi --disable-negotiation --disable-imap
--disable-actions --disable-userdir --disable-alias --with-mpm=leader


PHP:
../configure --with-apxs2=/usr/local/apache/2.0.47/bin/apxs --disable-cli
--with-config-file-path=/etc --disable-short-tags --disable-all
--enable-inline-optimization


A first question could be: was it wise to choose "leader" as the mpm on
a Linux system?

Then, which StartServers, MaxClients, MinSpareThreads etc. settings are
best for my scenario (can I use these at all for "leader"?)?

What else to consider? Any hints anyone?

Thanks in advance!

--
Manuel