Looking to buy a Sporty Coupe around 15-25k.

Hey everyone, so im looking to upgrade my car (currently drive a 2008 mustang), and im looking for some help/opinions. My main criteria are:

1. Pretty powerful/good performance
2. Clean, very nice interior (the one thing i dislike about my mustang is the interior, its very bland).
3. Must be a 2 door, 4 seater, i cant go 2 seater for practicality reasons and i dont like the look of most 4 doors. Here are the cars im currently looking at:
4. 2008-2009 infiniti g37 coupe
5. 2008 Bmw 335i coupe
6. 2011 mazda 6
7. 2011 Mustang GT (Not really a fan of the interior furnish , but i love mustangs!)

I'd love some recommendations and such from you guys, oh and im also looking for a manual, ive driven automatic all my life and il be learning manual soon from a friend to make the switch!

Thanks!