The pegasus has a very nice circular turret (4 cannons and 1 hardpoint) which could be used on leviathans, although the cingulum's 3 cannon turret could prove interesting too though.
As far as weapons are concerned, I would consider staying as close to canon as possible, so by pulse weaponry, what do you mean exactly?
AFAIK, the corvettes mount just about all energy weapons (as patrol ships often do, due to near lack of small bays/spinals), yet it might be a huge pain to set up an elaborate turret coverage taking account of all weapons... it's true however that given the curcumstances, all weapons might be candidates: the EPC has a very small range, but it can chew a fighter at point blank... on the other hand the NPC is longer ranged, so the fighter theoretically won't even be able to close in, I won't talk about the TPP as I don't know it well, but lasers and mass drivers are a must, as well as fighter missiles... I guess it all depends on tactics, but the booklets are not very talkative when it comes to that precise question.
I guess that a variety of turrets should be considered, each with their specific weapon loadout: pegasus type with 2 lasers, 2 mass drivers and 1 hard point, cingulum with 3 NPCs, Quad EPCs (perhaps near critical subsystems), etc...
