Welcome to the glorious world of Maemo!

I reside at the opposite side of the world and cannot help you with obtaining a device but stick around and sooner or later you will come across someone offering one near you.

Regarding your other questions -

1. N900 already runs Maemo 5, also known as Fremantle.
2. Here is another thread asking and answering nearly identical questions as you.
3. Here is a thread about removing bloatware. Tread carefully and read all posts, some packages are safe to remove only if you never intend to use the related services (e.g. Exchange).