Retrofit Mesa Options

Hello, I'm thinking of retrofitting an old punching machine, the machine only has 2 axis (X,Y) and the punching mechanism is manual but i'm thinking on making it semi auto/auto , my only experience with linuxcnc was on a retrofit using a complete ethercat solution , from servo drives to beckhoff ethercat i/o , so , in this project that solution is not very cost-effective , I'm trying to use most of the machine material , is this case is :
-2 Heidenhain 500pp encoder for feedback
-2 siemens ac motor's controlled by an analog Simodrive

In my research my first option would be a pc with a mesa 5I25 PCI card and a 7I77 card , the 7I77 card is capable of everything that I need for motion/feedback with a extra of i/o , does this option make sensor, or I'm missing something with this setup ? Recommendation or advice will are accepted .

The other question is , if I wanted to remove the PCI 5I25 for an Ethernet solution for "easy" exchange with other pc's , would the Mesa 7I92TH be a okay solution ? On the website, it says that it's compatible with the 7I77 card , but would the 7I92TH be a okay replacement for the 5I25 card ? 
i'm sorry for any wrong/stupid assumption that i  may be making in this post, but my knowledge on this topic is limited and recent , thanks for any feedback .

Thanks , that is a great advice , i will try to see what i can get my hand on .

from Mesa the 7i92TF and 7i77 are in stock
7i77

7i92TF