yeah all you need is a tach adapter, i have the autometer one attached to my msd window switch, it is the most reliable setup yiou can go with, all you need to do if you go with the autometer tach adapter, call them first for instructions, tell them your car. ie 99+mustang gt and they will tell you in a second how to install it.
MSD will modify their tach adaptor to work with COP ignition for around $30. I have a NX window switch, which is made by MSD, that was already modified for 1 cylinder operation (COP). All you have to do is splice into any of the negative wires going into your coils. Check out this thread I started about a week ago:
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