Dent Sport Garage in Norwood... They do springs all the time and charge a fixed fee of $250... Alignment wherever else convenient... I had my done at Dent and two guys banged it out in an hour. Its a tuning garage - so this is exactly the kind of stuff they do (versus Direct Tire (though great service there as well))...
http://www.dentsport.com
If you get the "knocking" sound, have the bolts re-tightened...
Goodluck!