If you get to the Prem with a non-all seater stadium you often get a new stadium built, rather than just a simple upgrade. But it does depend on how badly you have emptied the finances to get to the Prem!
As always, depends on what players you've got.
I personally play 3-5-2 attacking (think of the old CM01/02 formation) however 4-4-2 if you have the wingers to pull it off, is always a great option on FM10 with any team.
If desperate, 4-2-4 very attacking/overload is a good option. For final...