Selecting I/O cards

I was looking to get the Epic cards as they have well documented input and Output cards and they have just brought out a Gauges card that allows you to hook up real instruments. I have real engine instruments (Fuel, Oil Temp, Oil Pressure etc) so thought that these would be the cards to go with even though they are expensive.

However, I noticed that the Open Cockpit cards are just as god for the switches and lamps input and output, and I could put servos on my engine instruments and use the servo cards from OC. This would be much cheaper.

Has anyone used the Epic Gauge card?

How easy is it to add servos to engine instruments and calibrate with the OC Servo cards?

Are there any other I/O card sets you can recommend?

Thanks,
Stuart