chris8644:
Hey I have read that if your coil current is 100 milliamps or above one should use a mosfet instead of a transistor.
FIrst of all, a MOSFET is a transistor... maybe you mean a BJT.
Most BJTs can do way more than 100ma, even the small ones. They also make big ones with heatsinks for bigger jobs, although if you want to switch 10 amps a MOSFET is probably less trouble.
MOSFETs and old-fashioned BJT transistors have different characteristics. You should choose a type based on what you're actually doing.