Any v6 from 92-01 is gonna be reliable, some may argue one way or the other but the fact is they are ALL reliable, gen4 has some little issues here and there but so does the gen3. find one with low miles (sub 150K, yes, we consider 150 low mileage

). I cant sepak personally of the 3vz (92-93) but it has no more issues then the 1mz (94-01). check all fluids, especually the tranny fluid, this will likely have issues before the engine will. other then that you just have to find out as much as you can about teh car's history and condition.
now personally i like the look of the gen3 better, however, i perfer the interior of the gen4 (not for its looks). for your budget however, you can likely get a gen3 with lower miles and in better condition then the gen4.
others cars like the camry are the solara (camry coupe), es300 and avalon.