I found a picture of the 2011 geometry measured out and explained a bit clearer.
Given the numbers that the competitive cyclist calculator gave me for an eddy fit:
Top Tube Length 56.9 - 57.3 Cm
Seat Tube Range CC 53.4 - 53.9 Cm
Seat Tube Range CT 55 - 55.5 Cm
Stem Length 10.4 - 11 Cm
BB Saddle Position 74.6 - 76.6 Cm
Saddle Handlebar 55.5 - 56.1 Cm
Saddle Setback 4.2 - 4.6 Cm
Saddle Setback
Seatpost Type Not Setback
It seems to me the 54cm roubaix might need new parts to work ideally. Looks like I'd need a longer seatpost and stem to get myself in the right place. I know the geometry is a lot different but I tried a '09 tarmac and it immediately felt too big but part of that was the wide bars. I think I am going to shell out and get a professional fit before I drop any money on a new bike.
Thanks for all the replies!