Parallel ports

Is there any limit to the amount of parallel printer ports a computer can handle simultaneously? I have a computer with one parallel printer port built on the mainboard, I also have three different printers (I do a lot of printing work) and I am sick of having to swap cables all the time. I know that it is possible to buy a printer switch box but I don’t want to do that, instead I want to add two additional parallel ports to my system so I can run all three printers at the same time.

Is there any thing I will need to look out for when buying a "dual parallel port card" for my system? I don’t understand what this ECP/EPP stuff means, what card do you recommend?

Will there be any compatibility problems when I do this? Should I buy a PCI card, an ISA card or whichever I find first/cheapest?

Thankyou very much