hey, I'm not sure about the radius of the neck affecting the tone of the guitar significantly, if at all, although the wood that the fingerboard is made from has a huge effect, I like rock maple, it's hard and the notes seem to fly off it. Big hands are an asset, be glad you've got huge great hands like me, you can do huge eddie van halen stretches, and play complex chords, In many guitarist's views, the slim tapered neck is the best, as it allows the most freedom to move around (I personally like to sand my necks down to get some real speed moving around on there) As for wide necks, such as seen on classical guitars, I can only assume this is to promote easier fingerstlye play (although I have no factual knowledge regarding this) the strings are farther apart, therefore giving the picking fingers more freedom to move between them. I wouldnt recommend a larger neck, unless you're suffering problems with your existing one!