I've heard the seat bottoms are too tall. The room between the steering wheel and seat does not allow ample room for your legs. I've heard the SN95 (99-04) mustang seats work well, that is what I plan on using.
It can be done, however, you will need to modify the steel seat mounts on the floor, because they will sit up higher than you will want. Also make sure they don't have the optional side impact air bags, if the driverside is power you will need to decide if you want to wire it up (if you have a bad back you may want to for the power lumbar support).
You may want to consider using a 87-93 Fox body seat, and using the retro seat covers on the market so the upholstery matches your back seat and it looks more in the style. They should be cheaper then 2005 seats.