GWizard GWizard: A CNC Machinist's Calculator covers MRR. You can try googling "feed and speed calculator". No one calculator covers it all but between a couple of them you can probably get where you want to go.
Look at the K value on this one: Hougen Speed and Feed Calculator
This one is pretty good too, there are links for other calculators as well on that page: Milling Speed and Feed Calculator
With the Taig you are limited by rigidity. You are better off taking light cuts at faster feeds.