If you are going to upgrade, look for 2012+. IMHO, why bother upgrading to a now-dated 2007 3.0si.
With 2012, everything is still relevant in terms of looks and toys. A used one can be found for good money, after the typical hefty depreciation hit original owner (like me!) took.
Choices there are:
50i : 4.4L twin-turbo petrol
35i : 3.0L turbo petrol
35d: 3.0L turbo diesel
Here on forums, you would find people mostly talking about 35d and 50i. Strangely, not much talk about 35i. About all I can recall on them is the high pressure fuel pump issues. Lack of feedback on 35i is either a sign of better reliability or simply 50i/35d owners just being more petrol heads (especially them diesel folks, a vocal bunch

).
Do your homework on drivetrain, as ard said. Then pick options and colors.