What XC90 gasoline??

Hello Volvo community, I am looking for a new vehicle to get several offers of an XC90. In addition, I am staying in the USA and the offers for a 04/05-er with max 40k miles at 20-25,000$. If I opt for an XC90 then this would accompany me in 1-2 years after D. Here there are essentially 2 engines – the 2.5l and a T6 with 2.9L TWIN TURBO. Which engine would be the better choice (also with regard to the engine Needs)? Are there any special features you should pay attention to? Is the Navi also usable in D? Thank you for the help VBeach