Hi, I'm relatively new to CNC as well, but my limited experience tells me to use the highest quality vs the desired output you can get. I use a DeWalt router that is over 2 hp. I've seen spindles that are water cooled in lots of applications. I figure if the machine is running continually, you'll want a spindle that is cooled with more than the internal fan like a router would have. Lots of heat is generated in machining, even in the small projects I do. You'll get a good return on the investment when you're not stalled from overheating.