I do not know of any such list but I have looked up the a couple of ships in order to plan weapon loadouts for a
maximum-fun campaign:
<pre><font size=1 face=Courier>ship capacity recharge nickname
-----------------------------------------------------
Starflier 1000 95 ge_fighter_power01
Patriot 1300 126 li_fighter_power01
Defender 1500 157 li_elite_power01
Dagger 1800 183 bw_fighter_power01
Crusader 2500 248 br_elite_power01
Drake 2900 290 ku_fighter_power01
Barracuda 3400 345 bh_elite_power01
Dragon 3400 345 ku_elite_power01
Anubis 4000 395 or_elite_power01 </font></pre>
As regards your statement about having a longer duration of fire with weak weapons: let's say a loadout with maximum-class weapons drains your powerplant within 10 seconds; a loadout with 'optimum class' weapons will then take 20 to 30 seconds to do the same damage at the target. Why would anyone want that?
The longer you have to shoot at your enemy the longer your window of exposure. Also, unless you fly a ship that is much more agile than the target you cannot fire continuously; instead there will be a window of opportunity where you can hit your enemy and then you have to manoeuver again to produce another opportunity. During the window of opportunity you normally want to do the maximum possible damage; the powerplant can recharge during the rest of the time. If you use weaker guns then you have to fly more passes against the target.
Note: gun efficiency ranges from 2.66 (Rheinland Stealthblades) to 6.00 (FA Vultures); although this is somewhat related to the topic it is still a different battlefield.