Many thanks for the suggestion. I had actually looked at the Cmod A7-35T board (comparable in physical size and shape to the Mercury) during my search. The only concern is that I plan to design a board around an FPGA and I would like it to have the footprints for the FPGA on-board, but also have the DIP headers to allow the module to be plugged into it. Once the design is complete and functioning I will populate the FPGA circuitry on my board and remove the module. Therefore, I must be able to duplicate much of the circuitry from the module on my motherboard. Unfortunately it appears the Xilinx XC7A35T only comes in BGA packages, which I currently do not have the technology to populate. It's a pretty dumb reason, I know, but for my project this is more important than the number of logic elements. I do not anticipate my program will be all that large, so the Mercury board should be sufficient. I also have experience with the Spartan series of FPGAs, so the Mercury was an obvious choice to begin with. Additionally I really need the 8 ADC channels that are built-in, whereas the Cmod board only has two. I know I could probably put in an external ADC but why bother if there's a board with it already built in that would still suit my needs?
I am not set on the Mercury, per se, but it seems to be the best choice for my project at this point.
Also, to mark2112, ignore the second question. I figured out the level shifting.