I think that is a great choice. However not to throw a wrench in there, here is another option. Since you will be getting the same deal as me, why not go with SRAM Force and save the $450 difference with Red.

SRAM Force- 2113g
Shimano Ultegra SL- 2469g

You save about the same about of $$$ as you were originally thinking, but you get a much better groupo with the Force. Also you are only loosing about 140g between the Force and Red. As Triguy mentioned I would then spec out other components that you might want instead in the future. KCNC brakes, maybe a DA crank or a lighter crank, a DA cassette...etc. If you want a balance between cost and function, this might be another option. I think SRAM with its double tap is something worth getting over the Shimano groupset. Just my opinion.