In reply to gammarus:
What kit you need to take will depend greatly on the amount of snow that falls this winter, the time in summer you go, the route you take etc. If it's early summer and it was a very snowy winter then you might find your planned route is made much harder by unmelted snow.
Depends a bit also on the temperament of the people you are going with. Some people will happily walk along a well-trod path across a snow field in trainers with a walking stick even if the incline is enough that a slip would a nasty slide into rocks at the bottom. Other people would only cross the same path with crampons and ice axe.
I would suggest taking the alpine kit with you and going into the tourist office on day 1 and saying "we want to do a 6 day rucksack route, ideally without snow, we though of routes X, Y or Z, which of these are snow-free just now?". Tourist info should know all about that and anything they don't know, they can find out by calling the pertinent hut which will most certainly know the state of all paths near to them.
Then, based on what the current status quo is, you can decide to leave the alpine gear behind, or not, and decide which route to do.