Honda passport. Reliable?

I want to buy one for going to work/school and occasional camping/offroading
it has 150k miles and from 1999.

My other choices are infiniti qx4 or chevy blazer.

I haven't seen passports much so id like to know more

I would say so: 1999 Passport has a reliable record compare with other Honda models for the same year. I haven't seen much complains that would declare a void to own one.

Have an inspection and get an estimate of repair will give you a general view of the vehicle condition. I have included two link for your viewing about the Passport. You can do the same for the other two models:
http://www.carcomplaints.com/Honda/Passport/1999/
http://www.automd.com/tsb/honda_m/passport_mm/1999_y/