That's a pretty broad spectrum of ships. What would you like to do in the game?
Freelancer:
There's 3 variants, but one of those, the mis, you can no longer get. So, I'll talk about the ones you can.
1) DUR - The dur is the cheapest upgrade and is geared towards exploration, with a loss of cargo space, but a better jump drive and more fuel efficiency.
2) MAX - the MAX is mainly for gargo transport with double the cargo space, and more thrusters.
Of course you can just stick with a stock freelancer and upgrade it in game.
300 series:
The 300 hundred series is a step up from the Aurora, and offers more comfort and better specialization.
300i: Jack of all trades, and I'll leave it at that. But something you will have to upgrade in game.
315p: made for exploration, this comes with a jump drive and a jump scanner. Plus better thrusters and a bigger power plant for all that upgrading goodness.
325a: This is the fighter of the 300 series, which I don't think you'll be interested in because you own a hornet, so I'm going to skip it.
350r: Not for sale currently, but It's made for racing.
Aurora:
Everything the 300 series is, but on a budget.
Cutlass:
The cutlass is a a more maneuverable form of the freelancer. I'm not going to go into too much detail, because the variants are to be released soon. As of now, it's kind of nerfed compared to the freelancer. So any stats you see on it now will most definitely be changed in the future.
Avenger:
Also a fighter, it has more cargo though, but that is mostly the prisoner pods that it contains. This ship is meant for bounty hunting, if you're a good guy, but can also be used for smuggling live cargo, if you know what I mean . But again, it's a fighter, so it's kind of redundant with your hornet.
Conclusion:
I would personally go for either the Freelancer, 300i, 315p, or the cutlass. These ships are not technically fighters, though they can pack a punch. And depending on how you outfit them, they can really help you start a career. But, if I were truly narrowing it down, I would say the freelancer, either stock or the MAX, because that would really help you start off a career in transport and trade, and the economy will be a huge part of the game. (*SPECULATION*) But to be honest, it all comes down to your budget and how much you want to spend.
See you in the 'verse