The initial idea is for a Noruff sized vessel with similar if not identical armour but slower at 7/11
Roc
Nose
4 x ER large laser – 48 heat
4 x Medium pulse laser – 16 heat
4 x LRM 20 + artemis – 8 tons of ammo – 24 heat
2 x Gauss rifle + 6 tons of ammo
2 AMS + 2 tons of ammo
89 tons of weapons
90 heat
LW/RW
2 x Gauss Rifle + 6 tons of ammo (30 tons)
2 x Large pulse laser – 20 heat
2 x AMS + 2 tons of ammo
45 tons of weapons
22 heat
LW/RW Aft
1 x ER large laser
2 x Streak SRM-6 + 2 tons ammo
2 AMS + 2 tons ammo
19 tons
20 heat
Aft
2 x Gauss – 6 tons of ammo
2 x LRM-15 + artemis + 4 tons of ammo
4 x ER Medium laser
2 x AMS + 2 tons of ammo
50 tons of weapons
22 heat
196 heat generated total 192 dissipated
248 tons of weapons
after downgrading the engine but taking into the weapons weight difference you're left with 73 tons left over, but there's all the other calculations and stuff which i'm not sure about like the crew etc.
I'd be tempted to consolidate her cargo into a single bay and if possible put a small craft bay on her, but that's probably going to make things very tight.