Which fronts should I get?

You might want to consider adding some Song Towers to your list.

Good speakers, have you heard all three? Are you buying new?

If you are a "sound quality guy", used speakers should be considered. Is your budget $2000 more or less?

Have you checked the Def. Tech. site and checked the new BP8060's? I have a pair BP7004's that I really. The BP8060's from what I read would be something that you need to really check out.

If you are committed to the store, your decision should be what sounds best to you. Does your store offer other brands? I think you MAY be missing the "sound quality" mark without other considerations.

As I'm a self-admitted speaker junkie (see link in my signature), all I can tell you is that sound quality is subjective and the only person that can tell which if any of those speakers is right for you, is you. Bring a compilation CD or two of your favorite music to the store, and listen to all three. It is important that you use your own music and not rely on a dealer demo disc, since you will know what you expect your music to sound like. Its easiest to A / B compare the first two pairs; pick the winner and then A /B the winner against the third pair; pick the winner between those two and there ya go.

One word of caution with the Martin Logan's. Their smaller panel speakers don't do well with complex music, rock, or high volumes. The thin membrane used in the ESL panel simply can't move enough air. To make up for the small excursion of the membrane, you need a rather large panel with more surface area. ESL speakers also have a small sweet spot, so the sound quality is going to diminish more with this speaker when you are off center or standing than most dynamic driver speakers.

Oh, and be sure to cover those concrete floors with carpet / rugs to improve the sound quality of the room.