Anyone Recommend a Good Helmet Cam?

[Mad Jax]

So I'm putting auction bids on a mid 2000s soft tail Iron Horse Slammer and I'm looking for a good helmet cam to record some of the riding footage. Unfortunately it seems like consumer reviews are all over the place and hard to determine if it's an issue of not knowing the tech or if the cams are as good as the five stars or as bad as the one stars.

I'm definitely putting as much emphasis on sound as I am visuals. Its going to have a 1440 cc V-Twin and I want to really capture that deep rumble. I hate the bulk of the go-pros and prefer the cylindrical models, but I'm open to any feedback.