I agree with foster911, Tonica Fugata is an excellent software for SATB arrangements.
What he did not mention – I'm not sure he's aware of it, I'll PM him as well – is that the RBS release of Tonica 11 works patching a dll that remains unchanged in Tonica 12, so you can download the trial of the last version of the program and use it as it was registered.
Let's not tell it to the Capella developers!