I'm running MII front spindles as well on my EM.
Solid disks on the front of a car like a cobra is a definite no no. They are primarily for drag cars that only need to stop once and then have time to dissipate the heat. You will warp solid rotors on the street with agressive driving and they won't last 2 laps on the track or autocrossing before warping. The vented Granada rotors and a quality set of pads are a much better choice for this applation. Cheaper, too. If you want to run Wilwood calipers, look into running vented discs.
You also need to consider how you plan to use the car. If you are running 15" tires on the street, you won't have enough grip to use anything more exotic than the 11" setup (and discs in the rear) using good pads and fluid. Although you can never have too much when it comes to brakes, the multipiston aftermarket setups are just overkill without enough tire to take advantage of the increased braking force. But they sure look nice
If you want still more stopping power, Baer makes a few different bolt on kits for the MII spindle, ranging from sliding calipers like the OEM's use (PBR calipers) to solid mounted 4 and 6 piston monolithic calipers (Alcon). I believe Wilwood makes a kit with vented rotors that fits the MII spindle, too.
If you are up to some custom fabrication and want a good, yet affordable solution, you can buy a set of 11 or 12" vented rotors, machine some aluminum hats to mount them on the MII spindle and fit a pair of PBR calipers as found on the late model cobra mustangs, corvettes, etc. Parts should run you less than $500 but you'll need some custom machining to produce the hats and caliper brackets.
Here's a very good article detailing the installation of a full Baer setup on a car with MII spindles and a 9" out back using 12" rotors all around. Excellent photos too. :
http://www.baer.com/catalog/magazines/SRB_10_2000.PDF
You will need Adobe Reader to view it. If you don't have it you can download it for free
here
You can also view
Baer's Application Guide which shows the kits they have available and pricing.
Mike