Mike Congrats! You will love the CLX450.
As far as exposure protection for Monterey, the more the better. As Mike mentioned on our dives this weekend it was 54, which is warm from what I have seen. However if you do plan to dive in Carmel (deeper waters), or off of a boat I would have to assume that finding 54F waters is going to be a lot more difficult. You also have to consider the effects of pressure at depth on the neoprene. If you are going to buy anything and plan to use it many places I would suggest a 7mil (non-farmer john's style) wetsuit with a 7mm hooded vest. This way in cold places you can use the hooded vest, and in warmer places like SoCal you can ditch the hooded vest.
The most important thing you can do is maintain your core body temperature, even if you can handle the colder temperatures mentally.
As far as exposure protection for Monterey, the more the better. As Mike mentioned on our dives this weekend it was 54, which is warm from what I have seen. However if you do plan to dive in Carmel (deeper waters), or off of a boat I would have to assume that finding 54F waters is going to be a lot more difficult. You also have to consider the effects of pressure at depth on the neoprene. If you are going to buy anything and plan to use it many places I would suggest a 7mil (non-farmer john's style) wetsuit with a 7mm hooded vest. This way in cold places you can use the hooded vest, and in warmer places like SoCal you can ditch the hooded vest.
The most important thing you can do is maintain your core body temperature, even if you can handle the colder temperatures mentally.