7i96s or anything more?

Just a couple of weeks into LinuxCNC and it feels a lot less alien to me but there is a lot to learn. Got myself an old computer with parallel port but it seems to have latency on the higher side- 25k. Since I am willing to learn this thing, I thought I would rather get myself a Mesa board than searching for compatible parallel port cards or searching for a pc that has low latency. 

I have a mini lathe which has an encoder on the spindle. The spindle speed is controlled manually instead if hooking up to a VFD or similar (maybe a project for the future). Mesa has a lot of cards which is quite confusing to me, some are ethernet controlled, some are PCI. Not entirely sure which card will be of use to me, but it seems like 7i96s is the one for my usage for now. There are lots of members who pair up different types of cards for specific purposes. Not so sure about it if I need any cards to pair with either. Would like to know of the recommendations here.Thanks in advance.

A 7i96s will get you pretty far, if you need more inputs and outputs you can always combine it with a Mesa 7i84 board.

Mesa started making pci/pcie cards, then the made the 7i92 ethernet card which more or less was the same as their PCIe cards and needs daughter cards connected. Then they released the 7i76e  which was equivalent to a 7i92 + 7i76. If you needed to control 0-10v servos, you used a 7i77 with the 7i92.
Now with chip availability, they have moved on. The 7i96s is a great entry level card. It includes a spindle control and encoder. The earlier 7i96 was missing spindle control. It has fewer inputs and outputs than the old 7i76e but more than enough for a lathe. Its outputs are SSRs so in many cases it is not necessary to use external relays that you needed on earlier cards. It supports 1 daughter card and also the smart serial interface. You can't go wrong. There is no practical difference beween a PCIe card or ethernet.