Hi Karla and welcome to the forum.
An IVA is decided upon individual circumstances, some of us are employed, some not. The usual criteria is that you should owe more than £15k. This can either be to three creditors or more, or two creditors if you have more than two lines of credit.
Charges are made by the IVA company and I have no idea of the amount they charge. An IVA is usually over 5 years.
I recommend that you contact a professional, either by clicking on the expert link on the left hand side of the page, or by visiting
www.iva.com for a list of companies and reviews. Give one or two a ring and you will receive free and impartial advice as to all the options open to you.
If you could give us some indication of your debts and income, we may be able to advise further here.