I'll try to simplify this for you. Diameter is all about pitch, depth is all about overtones. This applies generally across all drums, but it relates to bass drums specifically as follows;
Diameter: Bigger diameter = lower frequency oscillation of the head = lower pitch & moving more air. Of course, diameter doesn't completely dictate pitch, that's down to tuning, but it does dictate the effective range.
Depth: More depth = more overtones. It doesn't make the drum louder. A shallow drum has less overtones & therefore produces a cleaner fundamental tone. The deeper the drum. the more overtones it produces. Some are useful, some you don't want. Getting a deeper bass drum to sound good is all about management of overtones. That's a tuning, head selection, & drum design process.
Tuning, diameter & depth all affect the way the drum feels, as well as how the drum sounds. As for advising you on your specific circumstances, that's difficult without knowing exactly what you're trying to achieve. You state "most power", well, that can mean many things. Deeper sound? Louder? Lower pitch?
The straight truth is, your existing bass drum size is more than capable of delivering a great sound. As for head selection, that's down to the specific sound you're after. As a general rule, if you want more balls to your bass drum sound, use a pre muffled batter head. Tune it to the point were you're getting a tone out of the drum, then tune it higher by about 1/4 turn per lug all round. Tune up the reso head in the same way, but a little higher. For unmic'd work, keep the reso head intact. Even for mic'd work, a full reso head will give your drum more body. If all you want is punch, & it's going through a good PA system, then a 4" port to one side of the reso head may help with that. Personally, I prefer to additionally mic the batter head to put more definition into the sound if needed.
Such a general question, so here's my general answer. Hope it helps.