God, I love the internet. Why can only a few people here understand the English language (no offense to non-native speakers)??

To the OP- go with an Avid BB7 brake and any wheel you like that can handle the rotor. This is arguably the best mech disc brake and can be had for about $50. The BB7 will fit either an ISO or post mount fork. Look at an Avid SpeedDial or FR5 hand lever. Have fun in the snow!