Hamsters aren't a bad idea.
I get the feeling that you're after a pet that you can interact a little with, so a hamster would be better than something that doesn't do much, like a fish or insects.
The only thing you have to be aware of with a hamster, is that they are very very good at escaping. If you don't close their cages properly, they will attempt to escape at night. Furthermore, even if they don't have an escape route, they may try to make one.
I had a syrian hamster, and it had no escape route, but had a cage with metal bars, and it would chew through them. It took him months and months, but you could be certain that at night there was the constant clanging of metal bars being twanged back and forth, so they can be noisy (which may be more annoying if you're in a trailer).
The biggest downside however is that hamsters still only have an average lifespan of 2-3 years, so they don't live too long. So if you're wanting a long relationship with a pet, then a hamster might not be the way to go.
Guinea Pigs aren't a bad idea, provided you have a reasonably grassy area for them, that will stay grassy for most of the year.
You'd need a hutch for them to stay in, especially if it gets cold at winter, and definitely a guinea pig outdoor cage for them, which you can put them in and give them a bit of room to move around in, but not be in danger of wild animals or local cats.
However, it's usually recommended that you have 2 of them at least, as they are social creatures and get lonely.
But they are also perfectly safe for you to bring into the house to play too.
Furthermore, they're easy to clean up after. Like most rodents, they poo pellets, so it's not a big mess.
Rabbits may also be of similar benefit to you, but can usually be kept solitary. They require the same caging however.
You'd have to be on the lookout however for them digging. Not all rabbits are interested in digging, but some are, and they're very very good, and will escape. And unfortunately given your local wildlife, that could be disastrous.
I believe for the most part, female rabbits are more inclined to dig (it's them preparing to burrow for a nest).
My male rabbit wasn't interested in digging, but males have their own issues, in being incredibly horny. They will attempt to mate with anything, and as horrible as it is to say, you will find semen on objects they play with (or even on yourself if you let them climb over you), you'll probably want to keep them away from other pets, as they will try it on with them, especially smaller animals like Guinea Pigs, but also larger ones like cats and dogs, which may terrorise your pets. I don't know if you can have them neutered, but you probably can.
An alternative would be a rat. They can be really social and playful, and are also quite easy to clean up after.
Contrary to what you might think, they also don't really run away much or even explore too far, so you could keep one quite contently in your house without issue.
I don't have personal experience with these (although my mum does), so I can't really say much in regards for caring for them. But I don't believe they're too difficult.
