1. Get one that fits, and is drilled for brakes (if you're only using it for training).
2. Ride it.
3. **********
4. Profit (due to your hardcore training).

But seriously, what's your pricerange and do you care about steel versus aluminum? How much cash you have to spend, will greatly affect what bike you should get.

I'm not to familiar with the aluminum offering, but I'll just pass along the following:

Good steel options:
Wabi makes amazing bikes, and if I had the cash ($7-900) I'd go for that.
The Surly Steamroller is a great bike, costs about $720 for complete.
For a lower priced, but darned good, trainer bike the Mercier Kilo TT is more than worth it's price.

As far as aluminum, there are plenty of options but I'm not too familiar with them all.
One of best-priced offerings I've seen is the Motobecane Team Track ($800).