Have you gone the AU thermo's Wisey?
Usually its the EL/EF thermo's that fit well over the stock 32/33 radiators. Unsure if the 34's have a different sized rad or not.
INVRTD they are usually around $200 for a new aftermarket or under $100 for s/h from the wreckers.
Anything else.. I wouldn't go as I've tried and failed, 2 x 12" and 1 x 16" were fine in normal weather but as soon as temps pushed over 30degree's and the car hit a 'little' traffic temps headed north both with and without the a/c on.
Under 30degree's she was fine in traffic.
I did notice an improvement in economy ~30km/s per tank and throttle response did feel a little crisper compared to the stock fan.