Ok, what do you guys want to know? The easiest way is to find the job yourself and tell them that you'll be contracting. Then you can just get payroll done via some company (e.g. Harvey Nash who charges about 500 per time sheet. There are others but your costs here will probably be more like 800) or if not you can have your pick of agencies and negotiate the rate as low as you can.
A lot of agencies will try to set their fee at 20%, but there are companies out there that will do 7% (more than payrolling but not bad).
In Switzerland even consulting agencies have to deduct vacation from your check and pay it back when you actually take a vacation, but you should be able to sign a form to wave that away (i.e. get rid of that deduction and not get paid for vacation).
Contract notice periods are usually one month. If you don't get extended and can't find another contract the normal unemployment rules apply (i.e. if you've worked for over a year you can begin drawing AHV immediately). I understand that according to swiss law you can switch contracting agencies at any time with no notice (the underlying contract has a one month notice period but who is carrying it can change during its lifetime).