Using a porter cable router to cut aluminum

Hi all, new to the group...seems like a very excellent group :-)

My name is John; I live in the Chicago area. I have a nice compound
milling table that I would like to use in a very simple cnc setup.
My plan is to fabricate a very sturdy z axis for a porter cable
router (1.75 hp), use the compound milling table as my x-y axis. I
have 2 nema34 173 oz in stepper motors for the xy, still have yet to
get the z motors. I also have yet to get the controllers or power
supply. I have a 1 GHz pc dedicated to my shop needs.

I plan on cutting odd shaped holes (1.5"x2.5") into 1/4 and 1/2 inch
6061 aluminum. I also would like this setup to be able to assist me
in making a much better cnc sysem (when wife approved funds become
available).

Question: Does anyone see flaws in my idea? Will I be able to cut
holes of this size in aluminum (if I go slow and keep lubricant
constantly sprayed on the metal)? Any suggestions on how to
fabricate a z axis that will hold a porter cable router (simple
plans??)

Thanks all...sorry for such newbie questions