Yes it can be done if you have the right stereo equipment. First ... I doubt that Ford used different doors depending on the stereo so you would probably just need to cut the panel openings. What stands out to me first and foremost and please someone correct me if I am wrong is this ...
How many channels (speaker outs) are on your jvc head unit? You have to keep Ohm ratings in mind here. The more speakers you add, the more Ohm resistance you are adding. Add too many Ohms and you burn out your stereo.
Are you going to be running an amplifier? Will that amplifier utilize RCA inputs (Low Level) or speaker inputs (high level)?
If your head unit has RCA out jacks then I would strongly urge you to use them to get your music to an amplifier, then power the door subs from the amp speaker outputs. Be careful as to the power of the amplifier so to ensure that you don't immediately blow the door subs. I doubt they are more than 25W each as I have not looked at them or tested them but I have heard them.
In short ... Yes you can make it work, just do it right and have no regrets later.
I have 25 years experience installing a wide variety of automotive electronics and this is the best advice I can offer, maybe someone else will know more about this system in particular.
1st Mustang - 1989 25th Anniversary LX 5.0 V8 - cats removed/ B&M shift kit/ 3.73 gears/ Cherry Bomb Glass Packs/ CAI/ UDP/ Performance Chip/ '91 GT wheels
2nd Mustang - 2002 Mustang 3.8 V6 - extensive mods (sold)
Current ride - 2005 Mustang GT Premium (Daily Driver) - Black Raven w/ red leather interior/My Color Gauge Option/Shaker 1000/ UDP's/ K&N Drop-in
Planning to add: Flowmaster American Thunder axle back/ Tuner