Given a reasonable amount of money (say, nothing over 15000 USD), what is the best mining rig with taking into account the rising difficultly and rise in price (also, please don't redirect to The Genesis Block, I want to here what people have to say, not numbers).
Obviously you are looking for a preorder that will be delivered to you around march and that only if you are lucky
So because we talk about preorders taking into account the reputation and past performance on delivering things is what you should look for.
Tl;dr: Buy bitcoins instead of miners