low temp
I smoked some white fish last year @ 130. (made smoked fish dip out of it).
I lit a top down fire with my electric hoop lighter from ACE hardware.
I used the BBQ Guru to manage the temp.
The Top was at about 1/8-1/16 turn.
I don't recall any issues with keeping the temp steady.
Without the BBQ Guru, I'd assume you'd have to light a small amount of coal on top and slowly get her to temp with the bottom vent open very slightly and the top at 1/8 or so.
Oh... BTW... if you smoke fish like this, be sure to heat the KK up for a while after you are done, else it'll smell like a fish mongers apron.