You should be more specific about which subwoofers you mean, as, for example, Dayton makes more than one 12" subwoofer; presumably, you mean this one:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-635
I doubt you are going to find proper measurements of all three subwoofers, so it will be impossible to give a definitive answer to your question. Many times in life, one must make decisions based upon incomplete information.
My advice is to search for proper measurements, though maybe someone here can help with that.
If I were to hazard a guess (and keep in mind, this is a guess), if you could get them all for the same price, I would think the BIC would be best. But for the same price, you might very well be able to get two of the Monoprice subwoofers instead, and that might be better.
I personally think it would probably be better still to wait until you have a budget around $500 or so and get something really quite decent.