If you are doing 2 1/2 gallon batches get a 8 gal kettle, you'll be glad you did.
I brew mostly 3 gallons and use an 8 gallon pot with a wilserbrewer bag. No recirculation. Ferment in a 5 gal bubbler. I have 2- 3 gal fermonsters and 2 1/2 gallons were tight especially with big beers.
The 3 gal...