Driver Board Advice

Hi, I'm converting a mill to CNC. 3 axis to start, hopefully add a fourth in the future. Also has a 0-10v spindle speed control. I want to use ClearPath SDSK servos which have Enable+, Enable-, (energize motor windings) Input A+, Input A-, (Direction) and Input B+, Input B- (Step) inputs. I would prefer to use a computer I have lying around and avoid purchasing a PC. Those include a Dell Inspiron 5558 laptop, and an older than dirt HP Pavilion a4316f tower. I see that laptops aren't recommended due to latency issues. Is that still the case if an ethernet card like a 7i96s is used? Is the ancient tower PC with a PCI card actually a more robust option? The selection of Mesa PCI cards is confusing, although it may be a mute point since most are out of stock anyway. Are there other well supported driver cards? Thanks for your help.