I've used the Sena SMH10, I wouldn't recommend the SMH10r due to the following. SMH10 is a slightly bulky unit with an excellent jogger dial you can use even with gloves easily. The SMH10r is a slimline unit but the battery is separate and needs to also be mounted to the helmet, in other words the smh10r has 2 pieces to attach on the outside of the helmet. Battery time is decent, I would definitely take a charger with you if your planning a road trip past a few hours.
A year ago I found smh10 on ebay for 225 for the pair not sure if prices have come down.
SMH10 can be paired up to 3 others but requires a specific sequence of pairings with each to work. You can have it paired with 4 people total but talk is usually between 2 people. There is a way to set it up so everyone can talk, but it's been a little while and I forgot how to do it. Kind of a pain but can be done. The wind noise and such I don't think will be an issue since even on a racebike at the track, I use this to instruct others and it works great....
One thing I would do is take your helmet to a shop where they have intercom kits and lightly attach the speaker into the helmet, make sure it fits "comfortably". Any kind of "pushing" against the ear may be ok while trying it on, but an hour or two later down the road can become quite painfull. Different helmets obviously use different types and shapes/fits for padding.
On another note, I believe the SMH10 is supposedly waterproof, however mine wasn't working after a couple of months of ownership and getting caught in some rain. I had purchased mine on ebay so I took it as a loss. But I have seen others with no issues..... it may have just been my lucky day.
