Are there any disadvantages to using Mesa ethernet boards over using a PCI board?

[JAZZCNC]

Is 1A enough to do everything? Thanks for the links.

How long is a piece of string.? Nobody can answer that unless they know what "everything" is.? Only you know what you are going to add to the machine and what current each "Thing" will draw.!
However, based on experience I can tell you 1A is on the low side. I'd go 2.5A minimum and ideally 5A to allow for future additions. That said always check the current draw of what your fitting to check you have enough spare capacity.