#tribikes

I need some bike advice from knowledgeable, non-salesperson perspective.  I pretty much know nothing about bikes and am learning as I'm shopping.

I bought my road bike about 6 or 7 years ago before I had any idea I'd be racing with it.  I didn't do my due diligence shopping and I went to the wrong store.  It doesn't even fit me correctly, way too big, so this is my first experience shopping around.

I'm at the low price end, but I'm hoping to find something that can work with me for at least 2 or 3 years before I upgrade.

Here's what I'm choosing between:

1) A 2012 Trek Speed Concept.  It's $1500 brand new, it's just been sitting in the store and they'd like to get rid of it.  It has an aluminum frame with a carbon fork and fits nicely.  The sales person said it has better components that the other bike I'm looking at.

2) A 2013 QR Kilo. Its $1800 and all carbon. The sales guys says the trade-off for a carbon frame is lower quality components.  Then he backtracked and said the components are fine, they are just mixed & matched which is something he'd never do.  This one felt a little better than the Trek.

Next time I go back I'm going to put them through their paces on the trainer better.

So my question:  Is a few extra bucks worth it for an all carbon frame or should I go with better components?  Or should I save that extra money and it towards a good helmet or other things that could save me on time (or races). Hopefully this won't be a forever bike.

I'm not super fast, so I don't know how much of a difference the frames will actually make.  It needs to be able to take me to an IM maybe this year, certainly by 2015, and a bunch of 70.3's.  

I haven't finalized my racing plans, but most of my races will likely be hilly (Quassy & Timberman) and one mostly flatter.