Freeagent looks interesting. What's their customer support like? My accountant is about 90 GBP per month but I get extremely prompt responses from them on technical issues so I'm inclined to think they're worth it.
Freeagent have always responded pretty immediately but it's best to get an accountant [1] that supports Freeagent and you are then effectively paying for support. They use Get Satisfaction which is community and vendor run support [2].
It makes the accountants life a lot easier too (they get a slightly restricted login).
My accountant is the same, and gives me a discounted version of FreeAgent. These days I have considerably more complicated needs than I used to doing simply contracting, but I'd probably still use FA + the accountant anyway. I pair it with ReceiptBank, with which there is an acceptable (but not great) integration.