What style would be best for a 3 hour mash?

Hi,

I want to brew two batches one after the other.
I only have one kettle to heat my water and boil.
So I thought to start mashing the 2nd batch while the first is already mashing. it would take 2.5-3 hours from that point until I sparge it (using the water heated by cooling the first batch).

What ale styles would benefit from such a mash? If I start high (69C/156F), would it make a large difference to the level of complex sugars?

I wanted to make an english brown and a belgian blond. Could one of these be done with a long mash?

(I think the brown needs a short mash, since it should have some dextrins)

Thanks!

Most modern malts convert in an hour or less so I don't think anything would be "better." However, some folks mash overnight with success so I don't think it's a problem. I might stay away from mashing darker malts for longer periods so do the brown first and the blond second. Is the base of the blond pilsner malt? If so, it needs a 90 minute boil so that might be another reason to do it second.

oh , I had a simpler idea. I'll simply keep the mash water in another cooler for 2 hours , and than start the mash...
I'll just have to heat it a few degrees more in advance.