sp77,
Yes you can use a caustic or water based quench for removal of SO2. However if you are dealing with a mist as opposed to a vapour then you I would suggest a mist eliminator be used after quench zone. This is due to the fact that sulfuric acid mist is very fine and can pass straight through a quench unit unless you are operating at a high pressure drop.
With respect to the cooling of the gas stream this is implied by using the term quench, but in any event provided you are not trying to quech an already saturated gas stream and the gas stream has temp greater than cooling water, you will attain cooling. With respect to the amount of cooling that is dependent on the inlet conditions of both streams of which I can not comment on.
You may also want to look at wet electrostatic precipitators as they are used for removinf mists and will produce a saturated gas stream at the exit.
If you wish more detailed response than this general one I would suggest that you provide more detailed information, this way people will be able to comment on amount of cooling you may get, what equipment would be suitable, etc.
Cheers.