Unfortunately, I don't no of a straight MT place in north Orange County. Central or South Orange have a few. However the following places may have what you are looking for in the area.
Erik Paulson's gym is in Yorba Linda near the corner of Imperial/LaPalma. Not straight MT but he teaches a well rounded course for MMA (Vale Tudo) as well as the CSW program. Top notch instruction. However, may not be the best if you are looking for only standup. The instruction is geared for MMA-type fighting.
You could check out LA Boxing on Harbor (1/2 mile north of Chapman) in Fullerton. Good conditioning aspects. All the instructors have fight experience. Both the boxing and kickboxing classes are grounded in basics. It's almost all bag work. Definitely above Tae Bo/cardio kickboxing but not a fight school. If you want to improve stand up to a smoker/competition level you would probably need to supplement the standard classes with privates. Nice availability of classes too (i.e. 3 1 hour classes M-Thurs after 5pm). There's also a new location in Yorba Linda (1-2 miles east of Yorba Linda on La Palma).
