Congratulations! I got my R53 a year ago June. It is more fun than should be allowed. There are myriad ways to modify the first gen MINI. There are numerous threads dedicated to everything from CAI to wheel offsets.

As for a spare, go with your comfort level. If a plug and some slime ona 120 degree day is ok, do that. If you prefer the security of a donut spare, there are several options. Off the top o my head Detroit Tuned has that setup available online. Here in Michigan, changing a flat in the middle of winter can be hazardous at best so I run runflat winters.

At any rate there are at least two threads here on MA for any one question you might have. Enjoy your new ride (I know you will) and don't let the mod bug bite you too hard. :-)

Motor On!
Chris