Most efficient accounting/tax software combination

I would like to reduce the donkey work involved in preparing accounts, then preparing CT return, SA return and P11d etc. I suspect that various bits of software fits together very well and can feed info through (eg Standard Name Format for unicorporated businesses). Has anyone had success with integrating company based software, and then feeding through to SA software for directors tax returns and P11ds?

Has anyone had to create a spreadsheet to automate the data-transfer process?

I am aware that Sage market themselves along these lines, but have also heard woes from users in terms of reliability and, of course, cost.

Your responses are very much appreciated

Kind regards

Accountant Southampton