Agreed. It comes back to what I said in another thread recently. Get the biggest standard engine, and if
that's too slow it's time to start tuning.
Yes, you can tune a 2.0 NA engine to give 200+ BHP if you really want to. It's not an engine I'd want in an Omega because it'd be as peaky as a peaky thing. (Nice in something lighter though

) The turbo route is an option but it'll end up costing the earth just to reach the level of performance a V6 will deliver and, whilst you could go beyond that for more cash, it won't be as refined as the V6 and, again, your insurance company will view it as a liability in comparison to a factory standard V6.
Kevin