I recently purchased an Optima with 850CCA but when the guy tested it, it read over 1000CCA!
They looked it up in a book, and said that it would be a good fit, despite the fact that it was a little smaller in dimension.
I just laid it down on its side and it is holding very well.

This is an "acid-free" battery with a 7-year warranty and I paid $120 from a local Batteries Plus. I know NAPA has them also for same price.

__________________
Current: '91 300TE 4MATIC 317k and climbing...
Former:
'81 300TD Wagon 168K "Tank"
'83 240D 216K 4spd manual "Da Bear" (aka best car ever)

"Never sweat the petty things...
and never pet the sweaty things."