I've tried some of the variants, but always went back to the MKIII. I fly a Griff version, the older "scuffed" one that isn't multi-decal, just because I like how it looks. But so far as I'm aware, that variant is only a cosmetic change from the same Cobra MKIII as the "strict" version of the game so far as it's specs.
Looking at your problem, it may not be the ship. Depends on how long you've been playing the game. Random Hits can be a bit challenging, depending on the level of opponent/contract you're doing it at. The "vengeance strikes" by the family or friends of people you've offed is part of that, so being outnumbered sometimes is pretty normal.
No offence intended if you're an old hand, but a little advice on fighting. If you're outnumbered by pirates with lasers, they "should" be able to slice right through your shields if you give them the chance. That's just a point of realism. Now, if you're injectoring straight away from them, trying to just outrun them.. Well, you don't fly faster than a laser. LOL If you fly in a straight path, it makes you an easy target, and once they have a bead on you, you're easy to cut down.
You want to fly evasively, while trying to get the drop on your opponents or get away from them. "Jinking" is making unpredictable little swerves while flying. Don't want to turn all the way around or anything, but something to keep your flight path from being a nice predictable straight line that's easy to shoot.
Now, have you maybe ever tried to shoot an incoming hardhead missile with your rear laser? It's hard to hit, because it comes in on a spiral course at you. You can do that too! I'm not sure exactly why, but the AI seems to be baffled more by roll moves than simple yaw/pitch moves. Might be because all 3 coordinates for your ship are changing rapidly in roll or spiral type manoeuvres. But the "why" doesn't matter so much, so long as it seems to work.
Now, some folks prefer to stay at a distance and pick off opponents before they actually actively come after you with careful longshots with the laser. Military laser has good range for that. But if you get jumped and they're coming in after you, that's no longer an option. My usual solution is to force an actual dogfight. Get in close, close enough that their collision avoidance starts kicking in and they start sort of wildly weaving all over to shake you off their tail. Slow down to match their speed, since it sucks to lose the fight by rear-ending your opponent's ship. LOL Then keep right on their tail, trying to follow every turn they make. That will make you really hard for their buddies to shoot, and every time you get the ship you're chasing in your sights, give it a short burst of laser. Eventually, that one will explode and you can pick the next nearest and dog after him/her, keeping tight on their "six" and cutting pieces off every time you get a good clear shot at their tail.
I've taken down some good sized groups of opponents that way, without using a single missile and without taking much damage. But if you're outnumbered, and it *might* be a bit more than you can handle all at once, sending a hardhead missile off after one or two of them will give them something to think about other than you for a bit while you even up the odds some.
Use your injectors in short bursts every time the opponent you're dogging at the moment turns in a way you didn't expect and gets a little ways away from you. Close that distance up fast, because if he's running from you and trying to avoid a collision, he isn't shooting at you. This "method" also allows you to really enjoy the graphics quality as seen in the details of your opponent's ship as you slice it to ribbons a bit at a time.
When you opponent's hull pops, don't spend too long enjoying the show of the explosion. Especially not if you're on your injectors at the moment. Running into the debris, cargo and etc from his ship can damage you just like a laser hit or a missile, and it sucks to get killed by the junk just a couple seconds after you actually won the fight. LOL I've done that little error more than a few times.
What I'm saying is the Cobra is a nice little ship and does usually handle fights well, especially when "iron assed" a bit. But when you're outnumbered, outgunned, or are up against something faster, then some "fancy flying" is in order. It's where the fun is.
Sleep? Who needs sleep? Got game. No need sleep.