Anything above tx650 is a cable mess. If your cabinet provides good cable management, the tx850v2 is a fine choice( and cheaper too).
Take high end mobo if you plan on OCing accordingly. Additionally, you will need a heavy cooler to manage your temps. A Maximus Formula with an Evo would look wierd. You will need a heavy cooler like a noctua atleast to exploit the features offered by the Formula (think higher costs now).
If you want 4.5ghz, a 11k asus p8z77m pro can do it with an evo.
Choose components according to you expected usage in future. Prioritize between gaming and OCing. Firmly decide on a budget first.We can stuff things within that range afterwards.
The 660ti sli maybe overkill now but its going to do fine in future. In a year or two, you would need to OC the hell out of the cpu and gpus to max out certain games just on a single monitor.
I believe Cabinet is a personal choice. Fix a budget for the cabinet first, select a few cabinets within that range, post them here for discussion. Its easier than eveyone suggesting their own choice to you.
If looks are also important, be ready to compromise on other features. You cant have a car that does 0-100kmph in 4 seconds , gives 50kmpl fuel mileage and costs as much as a nano.