Your choice should depend on the year/theater you mostly represent. I have attended 'farb feasts' and strict tactical engagements. There are two schools of thought: 1) bring a musket that is common to your unit, the unit you primarily portray, or even theater... as some guns were more common than others, depending on the year and theater of operations 2) bring whatever pretty gun you like (these guys are be-littled as 'farbs' most likely by those in category 1...), but most spectators wouldn't know the difference.
I have found the Enfield 1853 3-bander (made by Euroarms and Armisport) to be most common in my neck of the woods... I think the Armisport model weighs just a tad bit more, if memory serves me... neither of the models is an exact replica, as the gun stock is slightly different than the originals... so most more-serious reenactors replace pieces of the gun to resemble an original (this process is called 'de-farbing') ... and yes, I belong to a more strict group, as we attempt to be as authentic as possible to replicate the conditions our ancestors fought under... so, no modern conveniences of any type, especially in the clothing dept.. don't get me wrong, but we enjoy the laid back atmosphere of a few less-than-authentic/farby events every now and then.. it's really all about going out and trying to honor our ancestors, learning the hardships they endured, and forming friendships of a lifetime.