Definately the 160 watt bulb. If the temp is to hot just lower the basking spot, I just bought the exact same bulb last week and I keep it 14 - 15 inchs away form the lizzard when he is basking. Acoring to the instractions that you get with the bulb, your suposed to closely monitor how long he stays under the bulb to get a idea if your giving him to much heat/uvb/uva light. NOw what I did was get a zoo med lamp stand that will adjust perfectly to what ever you need. My aquarium is 75 gallons so yours should be close to the same size. spent about $88 including shipping for the lamp stand ceramic lamp and 160 watt bulb, Good Luck 
