No I don't think that would be necessary simply because if you are not from USA you also probably do not have a Tax identification number which is what a W-9 asks for not w-8
You need a W8 or W9 no matter which CPA network you apply to.. CPA networks need to keep track of it, for you and their own sake. This is also to protect the CPA network, to know that you are legit entity. CPA network will report do their accounting and report the same to IRS, while they will be obligated to give you the year end statement so you can pay taxes on money that you have made.
I'm from Europ I always need to fill in a W8. Does this just mean I don't have to pay taxes in the US. Will this make me pay taxes in my own country?
Since you are out of the country, you would not pay US tax. However, you may be liable for taxes in your country on your earnings. The companies will probably still need you to fill out a W9 just so they have on record you are not a US entity.
Non US people are supposed to Fill W8 BEN Form. You can download it here and also there is a tutorial on how to fill it: http://tricksmommy.com/2011/08/01/how-to-fill-a-w8-form-for-non-us-residents/