Last Supper must buy ticket in advance online. Most likely it will be sold out liao. Alternative way is to join the Day tour at 40-50 euro which includes the Last supper tour. I read that you can go and try your luck and wait at the counter to see if there is any empty slots to slot you in. They limit the no. of ppl in for a duration of 15min (if I remember correctly), so if that timing there is vacancy they will let you in though chance are very slim. The tour operators will book many tickets in advance that explain why always no ticket. If you take train remember to validate your ticket at one of those YELLOW BOX before you board the train else you might be fine even you have a ticket (but no stamp with the date n time).
From Florance you can tk a bus to the outlet mall (The Mall, about 1-1.5 hour) Bus station is near the Florance train station. From there take a taxi (5-10mins) to a train station and tk the train (30mins)then taxi (10-15mins) to the Prada outlet mall. The taxi driver will arrange to pick you up at your timing and send you back to the train station and then its a train ride back to Florance.
From Milian you can take a bus near the Castle to FOX TOWN outlet mall. there is a Casino next to it.
Done that 4-5 yars ago so can,t really remember all details liao. I am going Milian end of June might visit Terra cinque. Maybe go Florance too I like it there, the last time I stayed in the Majestic hotel just next to the station cheap (50 euro)n good free breakfast. Room is big too.
A side day trip to Siena from Florance by bus is nice too, thats the place where they have a horse race twice a year in the big square middle of the town. Its a medieval Town. http://en.wikipedia.org/wiki/Palio_di_Siena
Its not easy to find a supermarket in Italy do check with hotel where are they located.
Rome Station there is one. Behind Florance station (same building)there is one, opposite the road there is a cheap n good pizza n pasta restaurant, brightly lit and family style. Milan Dumo area don't remember seeing supermarket.