, It will cost you from 10,000 to 20,000 USD to open a free zone company (so that you can legally operate with your IT company in the UAE market ). Finding a job totally depends on your skills and connections, but I would say, finding a job in one week seems almost impossible.
There are a couple of things you can do,
1- Try applying for jobs ahead of time, even before you arrive to Dubai, apply to new jobs through recruiting agencies and job search engines
2- Let all your friends or aquanteces know of your visit, most people find a job by referal
3- If you can afford starting your own IT business in Dubai, go for it, just research Free zone business in Dubai and you will get to know all you need.