Congrats! I think most people opt for some Slime and an airpump, which you can get as a kit from PepBoys. I have that as well as plugs for holes that can't be repaired with the Slime. For longer trips, I bought a MC spare that I keep in the back seat footwell for when all else fails. Classic MINI is having a sale on the donut spares right now.
On a related topic, I recently bought a new tire gauge that is incredible. I've always hated most gauges because they always allow air to escape before getting a reading. I bought mine from Autosport but Griots sells their version which I probably would have bought if I did it a second time around. Cost was a hefty $60 but well worth it. Accurate to the tenth of a pound, and has a bleeder valve that you can bleed the pressure without removing it from the valve. Just hold the button until the correct digital reading. The valve portion just clips on and stays there so you don't have to hold it against the valve. Sometimes a tiny bit of air escapes, but it ends the frustration of getting a reading and losing a couple pounds of air first, lol.
c3:Lets Motor for a Worthy Cause ::: Find a MINI Motorer near you!