I have been wearing O'neill wetsuits since i was a kid surfing and diving, They make amazing dive line suits designed by and for divers tested in the NorCal waters. My 5mm replaced my 7 because its that warm. give them a look.
My quiver of suits :
O'neill J Type 7mm
O'neill Sector 5mm
O'neill Explore 3mm
Scubapro Tropical Steamer 1mm