Didn't realise people still did ngine swaps ahaha.
If the car is available with the engine you want then why wouldn't you just sell it and buy an S5, cost? Buying an S5 in the first place just seems the simpler way and you're guaranteed that everything will work as intended. You may run into issues otherwise when swapping, and it would still cost a lot on top of the car you've bought.
I would have thought switching an engine out would only be a worthwhile idea if the engine you're fitting is totally different, like putting a 5 litre V8 from an F-Type in or something ahaha