We got the same wheels but I bought Dunlop M2s. We'll have to compare notes after it snows... I installed them yesterday and with a 60 degree day and "new" tires they felt softer and quieter than the 070s . Dexter at Tire Rack was good to work with...
Also...the wheel/tire combination is heavier than stock but I guess we trade something to drive in the snow and ice.
I'd call first thing tomorrow and ask to speak to someone and get a person to answer your questions. If you have no names ask for Dexter. I believe Tire Rack is trying to maintain good customer relations and they should be glad to speak to you about a $1200 order.
I understand that the break in (wearing away the mold release chemicals) on tires is typically several hundred miles. You really need them ASAP with snow already coming down.
Good luck keeping the STi on the road.