Hi Drew,
I've not actually stayed in any of the campsites you mentioned so can't comment on the facilities offered but used to live in Vallandry so i know the area well.
Le Versoyen is in the middle of Bourg so for access to the funicular deffinetly the best option. The other two you mentioned are further out, Le Reclus is a good 10+ minute ride away. (EDIT – uphill at the end of the day. Shorter in the morning)
Camping Eden is in Landry – about a 20 minute ride to the funicular – but a nice location by the river.
I would also suggest the Nancroix camping, you can ride to it off the mountain at the end of the day. And down the road (5 minute roll) to Peisey lobsterpots to get to Vallandry lifts at the start of the day. And its by far the most stunning location.