More folklore !
The only way to go in Europe is diesel, Cockney Steve's comments are largely out of date, the issues that caused Thielert to go bust are now well understood and effectively over.
Gearbox and clutch life have increased and are not expensive to change with the unit being exchanged at the service life intervals. The 1.7 engine is no longer avalble ( but supported) so at life you have to fit the much more reliable 2.0 engine.
The Austro engine a bit of an overkill following the Thielert problems and so has a much increased weight and power however these balance each other out and the performance is much the same.
I would look for a DA40 with the 2.0 Theilert engine and a maintenance company that understands the engine as well as composite structure....... Finding a company that understands composite structure in the UK is the biggest ask !