I'm hoping to use reusables after about 6 weeks so have some new and Preloved Tots Bots Easyfit Stars, plus I got a brand new accessory kit on ebay. I also picked up a couple of Bumgenius elementals in a local secondhand baby shop - it really helped to be able to see the nappies to understand all the terminology! I did the Nappy Lady questionnaire too.
Re thermometers. The Tommee tippee ear one has been fine for 3 years. We also have a forehead one, but I normally test the ear.
We also used a bath thermometer as DH was uncomfortable checking it! Also useful as DD hated any bath less than 37 degrees...
One or two cardigans is plenty I'd say. We barely used them on a winter baby as our house is warm and when out, she was either in a jacket, star wrap or pram suit anyway.