I have really liked the s-coils they seem to work fairly well at reducing noise and vibration. My Hyperlight is only 29.75 axle to axle so it needed a slightly longer one that the typical s-coil. I bought a 7" I think, it has a short addition to it that you can use to make it a total of 7" long or you can take it out and have it only 5" long. Typically I only use the 5" piece any more unless sighting in and or tuning.
I will second the shoot your bow with every one they have and utilize the death grip I talked about in the other thread. It will help you feel the difference, you don't really need to stand any farther than 5 feet from the bale so do the first few shots with your eye's closed so you can really feel the bow.
Every one is different so take your time and make sure that you get one that really makes a difference. As far as hunting goes you will likely spend some time on the ground so the shortest one you can use within reason would be best.
I would also look into some vibration dampeners for your limbs. You can get actual limb savers or any other brand you like. I am really happy with my set that are made by bow jaxs. They are kinda as strict shaped. But I think most any would work fairly well. IF you can get away without a string leach of any kind you will be better off. A string leach is a rubber piece that is placed in your string, one up by the upper cam or wheel and one by the lower cam, they have a habit of falling apart and hitting you and people net to you. Usually in the eye for some reason. There are some that are made really well, so if you do get them, make sure they are really built well. They guy who services the bows should know off hand which ones tend to last the longest.
Good luck and take advantage of the shops help. If you have any question don't hesitate to ask.