I was looking at some ISO grips that I saw on someone's B650 and wondered if they would fit a 400. They look nice. I don't think I need heated grips so these seemed like the next logical choice.
Those grips sure do look great, and I've got to admit that they feel great too. But there are other solutions which may give you a better option from a cost/benefit perspective. Dave Reppert is the guy who makes Grip Buddies - neoprene wraps for your current grips. They fasten with velcro and don't migrate around the grip at all. They give you just a bit of extra cushion and don't either absorb water or interfere with heated grips for those who have them. The price is great and they've lasted me almost three years of daily commuting, so they've outlasted several pairs of gloves.