As sms has mentioned me I think I ought to jump in here..
I recently set-up my own graphic design business here from the UK. I kept UK clients so luckily earn uk money!!
To be freelance you need an entrepass as sms mentioned. Basically you have to submit a business plan, cashflow projections... blah blah blah.. you know the stuff. Same as what a bank manager wants!! If the company are going to employ you then they will have to apply for an employment pass for you. Pros and cons of both really. If you have entrepass and you like it you can stay (normally for 2 years then needs to be renewed). However I am not 100% sure if they will give you one just for a one off 10 month contract as that tends to be more of an contractual job and therefore not self-employed. That would entail the employer sorting out the EP for you and you can then only work for them. When the contract ends they will terminate your EP and off you go home. Simple and straightforward, subject to getting it in the first place.
I must admit that I followed the information on this site regarding submitting an entrepass application but I sent it in from the UK. I used a local company address (serviced office - I can give you the details if you want of them) and another local company to register the business once I had the approval in principle letter. It was all very straightforward with exception to one thing. The LOCAL bank. I will give you a warning.... to open a bank account is straightforward. To get some of them to provide you a guarantee letter (basically a £1000 / $3000 bond) is another thing. My bank (and I wont say here - PM me if you wanna know) took 6 weeks to do it and they charge you and I even provided them with the letter. USELESS is the polite word. As a fellow brit I'm sure you can imagine the other "polite" words I used. Just be careful because with that bond you can't get your pass and with the pass you can't work etc etc. A nice vicious little circle.
On a personal note I love it here. Warm climate, nice people, cheap food and transport, booze is pretty much the same price as in the uk and ciggies are marginally cheaper.
property to rent is cheaper than London in my opinion but the clubs, pubs etc aren't on a par. They're good but not as good. All in all if you want to experience a bit of culture, shops that open everyday till late and want to visit a few places in asia I'd say take it (depending on what salary they offer you). £1 is about $3 so we have it quite good. Tax is lower aswell - way lower than the uk, so you'll have extra benefits on that side.
Good luck and if you want to know more let me know and I'll see how I can help.
Don't p*ss me off! I am running out of places to hide the bodies.