Lily,
Don't be put off by the financial side, i worked about 2 years contract stuff waiting for my break into a staff position in the Oil game.
I used a company called "Payco" in Lancashire, check directory enquries they will give you the number and get them to send you an explanation pack out.
Dividends paid monthly, loads of expenses claimed for and i was better off to the tune of over a grand a month compared to the same people doing the same job on a PAYE basis, so they could ram there holiday and sick pay where the sun never shined.
If you are good at your job which i am sure you are, don't let the sniping worry you, every contract job i have ever been on i have been offered a full time staff position and declined it until the biggy i am in now came along and i took it with both hands.
Managers nowadays see the benefit in having a worthwhile employee regardless whether they are temp or perm. It is easier for them to "Try before they buy" and the 6 months will just be like a trial period.
I guarantee you are offered a full time staff position at the end of the term if they like what they see!!!