I've searched through this mailing list and the docs and all I have found so far
is how to change the MTU for WAN connections, hopefully someone might know
something about this:

This may sound like a strange request but here goes: I currently have a gigabit
LAN at home with jumbo frames, and I would need an MTU of 9014 for my Intel Pro
1000 card (currently in the box running m0n0wall 1.1).  My understanding is
jumbo frames needs to be set for every gigabit device (I have an unmanaged
gigabit, jumbo frame supported switch without VLANs) to have jumbo frames at
all, and it does speed up my transmissions on my LAN.

That being said, how do I set the Pro 1000 card to an MTU of 9014 in m0n0wall?

Also, I'd like to run an additional fast ethernet card to isolate gigabit and
100Mbps connections.  I assume m0n0wall allows the use of more than 2 LAN
network cards (plus the single WAN card)?