Off the shelf expresscard or cardbus cards for rs422/485 will do 921Kbit/sec which, depending on the protocol you use and its overhead, should get you more than 100Bytes of data in less than 2ms.
Considering the ease at which you can use RS422 with a microcontroller this is the first thing to try. You can even forgo a protocol and use the raw communications during development to get up and running quickly (though for robustness, a protocol that can handle errors and comms start and stop will be wanted).
Ethercat is the other option, which can use a standard ethernet card, (if you are lucky your laptop will use a compatible chipset), but you will need to add an Ethercat chip and ethernet phy on the microcontroller side. Additionally, Ethercat uses a robust but complicated communication protocol so it can take some time to learn. The benefit of doing so is that you have fast communications designed for realtime control.