I think Bridgestone also do an A001 all season tyre which will feel similar to your winter tyres, but I don't know if in runflat. The winter tyres are for below 7 degrees really, and over that they will deteriorate quite fast. I would have removed them in March for summer tyres.
Michelin are the dearest tyres of all usually, so wouldn't bother with them.
I took mine off runflats and it's great. You can get inflation kits for slower punctures, or good roadside cover. If worried, stick to runflats.
Firestone are an affordable runflat, or Avon too.