Based on the numbers you gave me, I would look for a 250# spring with a free length of 16" and a diameter of 5". That should give an effective wheel rate of 165# and be very close to maintaining your current ride height. Afco, Hypercoil, and Eibach are all quality springs. Before you put them in, wrap the ends with duct tape. That way if there needs to be an adjustment they won't be scratched up and you can return them. Just an FYI this isn't an exact science as far as keeping the ride height since there is no fine tuning like you can with a coil over. Not getting them right on the first shot is not uncommon but once there is a baseline, the second go around is a snap.