Torus34 said:
As soon as you include the word 'professional', as in 'professional landscape pics', your question becomes 'What camera(s) do professional landscape photographers use?'
My guess would be 6x6cm or larger size film cameras.
Personally I think it's too soon to worry about "professional". I don't want to throw a wet blanket on your aspirations, but it's easier if you think of it like a musical instrument or learning to fly an airplane. It takes someone a long time before they really need a Stradivarius or a Steinway & Sons. And when leanring to fly, you don't start with a stunt plane like the Extra 300. Sure, it gives you all sorts of options in your flying, and you aren't as limited in what kind of rolls, dives, and loops you can do; but when starting out, you don't need to pull 10Gs. Most people start in something like a Cessna trainer. It isn't sexy, but it does it's job well.
I know they aren't direct comparisons, but it's something to think about. Limited options can actually be useful when learning, and with something that usually takes a lot of practice before you are good enough to make money at it, it's usually smart to start off with something that doesn't break the bank.
But to answer your question, there are lots of different things pros use. Everyone chooses by what's important to them. Some will shoot 35mm because they want portability, others will shoot larger formats because they want the sharpest image possible. Some like rangerfinders, and other SLRs or TLRs. If you are starting out, it's hard to know what's going to be important to you, since there are so many variables and options available.
My suggestion would be to save that thousand and get something cheaper so that you can figure out what's important
to you, and then you can spend it on something you know will be right. You didn't mention if it had to be film or digital. If you want digital, I don't think there are any out there that cater specifically to landscape. You just need to find something that does wide angle. I went with a 10D several years ago, because I had already experimented and found that an SLR with a vertical grip combined with a 50mm lens and an 85mm was perfect for me to do people shots and portraits, which is my main focus. Since the 10D directly replaced my EOS5, it was an easy choice. If I were still doing landscapes, I'd still be using film and medium format, probably something like a Fuji GW690III 6x9 and a hand-held lightmeter, but again, that's what works for me after experimenting.
At this point, I'd get something that you can learn on. Even if you spend a lot of time at it, it can take years before you reach the level that people want to buy your images, and even then it isn't easy. If you're patient, you'll get there, though.