Sounds like you will be needing 26 inputs, the Mini-Pac has 28, so your good to go.
Word of advice, GET THE OPTIONAL WIRE HARNESS, I bought my Mini-Pac without the optional $10 wire harness because I thought since I've wired a I-Pac4 before I was more then capable.......WRONG!
The Mini-Pac is just that....MINI! The pins are so close together that you need a special sized molex just to mate it to the wires.
Save yourself some time, it's only around $10-$12 with the Mini-Pac, well worth it.
Enjoy and Good Luck!