Quick books is very good if you don't need to do tax returns online (which will save you money in the long run) We use Sage, but I would advise you get your accountant to set it up with you 1st, as its simple once explained, but getting the start details put in, once your year has started is a bit odd!
I bought VT Transaction £125+VAT recently for unlimited number of companies. I think they do a 30 day money back trial. I think it's easy to use, does VAT returns if needed. SAGE multi-company versions are pretty costly (£900 odd for 4 company version !)