I'm 180 pounds and 5'10, which dirt bike would best suite me?

5'10" is way too tall for a 150. The 450 is also way too much bike unless you are a very experienced rider. I have the CRF250R and CRF450R and prefer the 250 by a long shot. Just bought the 450 to run an extra cl. 450's break traction too easily for trail riding, I mean sure you can ride one but the 250F does way better. The 450 is also notorious for stalling in the woods. Ever tried to kick start a hot 450F in the woods? I don't recommend it. An XR is a fine choice for trail riding but is not suitable for the track. Also much heavier and slower than modern liquid-cooled bikes.