Don't go into either the AspX or the DBX with any intentions of doing combat.
Only ships you can destroy are the smaller ones and even then they have the advantage of being more nimble ships.
Best way I can put it is this:
Only time you're going to run into someone is while you're still in the bubble. Even then they're only going to try and interdict you. In which case you can just submit and boost out of there to safety.
What is more important are the shields. If your shields can tank the few shots that will land while you're running away then you're good to go.
I went from the Cobra to the DBX for a very short time. Didn't like it and decided the AspX seemed like a better ship.
But again neither of these ships can stand toe to toe with anything larger than it. The whole DBX having a 3 sized hardpoints. Phooey. It still can't hold it's own in any real combat scenario, CZ, RES, Compromised Navs.
this is going to run you pretty much what you have now. For exploring, you want the minimum. That's the best frame shift drive available. The rest being D Rated equipment so that they weigh the least.
After that you really only need a fuel scoop that doesn't take forever and a shield generator that doesn't kill your jump range but gives you enough protection to boost away.
If you haven't submitted to an interdiction before it's preeeetttyyyy easy.