Why not get the Expert (middle group) Ruby? There is no reason a recreational rider should not have Dura-Ace. The only reason I didn't buy the Dura Ace or Ultegra version of my bike was money. All I want to do is ride 3,500 a year and some centuries, but if my budget had been bigger I wouldn't have 105 right now.
From what I hear you would notice a difference between 105 or Dura-Ace. That being said, most reviews I have found on 105 are quite favorable. I find my shifting to be very smooth, but I have never rode Dura-Ace. There is a BIG difference between my old Sora and 105. Get what you are comfortable spending and don't worry about whether or not it is "too much bike".
Amanda
2011 Specialized Epic Comp 29er | Specialized Phenom | "Marie Laveau"
2007 Cannondale Synapse Carbon Road | Selle Italia Lady Gel Flow | "Miranda"
You don't have to be great to get started, but you do have to get started to be great. -Lee J. Colan