I had a similar problem with a Tac and wanted to pilot a Gorn ship.

I thought have cannons at first but decided against them after trying them out. As a Sci ship the Varanus gets 4 of the target sub system abilities. Two of those aren't the best, but targets weapons and shields are extremely useful, and they are free powers on a ship that only has two tac boff slots.

This character will hit Rep 5 tomorrow and I think I'm going to get him the Omega plasma torpedo and cutting beam, they will probably be useful in this setup. I haven't parsed with the current config, but I can tell you its putting out alot of DPS, 1,100dps from the each of the dual beam banks alone, unbuffed. Buffed they are well over 2k.

I've also chained the target subsystems and torpedo spread together so this ship always has at least one of those active.

Anyway, here it is. There's still room for improvement though. All the weapons will eventually be replace with fleet variants. I do have alot of shield and hull heals. The hull heals might be alittle redundant with the repair platform and might try out some powers once I get around to it.

Fore Weapons:
1 Photon Torpedo, 2x Dual Disruptor Beam banks Mk12

Aft Weapons:
3x Disruptor Turrets MkXI

Deflector:
Honor Guard Mk10

Impulse Engine:
Honor Guard Mk10

Shield:
Honor Guard Mk10

Devices:
Subspace Field Modulator
And whatever else you want

Engineering Consoles:
Plasmonic Leech, Borg Assimilated console, Repair Platform

Science Consoles:
Field Generator Mk11, Particle Generators Mk11 x3

Tactical Consoles:
Disruptor Induction Coil Mk11 x2

Boff Powers:

Tactical:
Tac Team 1, Torpedo Spread 2

Engineering:
Emergency Power Shields 1, Reverse Shield Polarity 1
Emergency Power Shields 1

Science:
Hazard Emitters 1, Transfer Shield Strength 2, Gravity well 1, Gravity Well 3
Polarize Hull 1, Hazard Emitters 2, Tyken's Rift 2