I just rimmed up my accord with some 18" ICW Racing rims with low-profile Pirelli's. I have about 2 - 2 1/2" room to lower my car and I was wondering if anyone had some suggestions on how low I should take it (without any serious mods).

I'd say no more than 1.5" of lowering with those wheels. Go to low & your suspension will be over-worked resulting in a shitty ride. The low profile tires effect ride quality since the tire sidewall is the 1st thing that absorbs bumps. Make sure to upgrade both springs and struts or go with a fully adjustable coilover kit, if you have the extra $$$.

Stick with the well known brands like : H&R, Koni, Neuspeed, Eibach, KYB, Bilstein, Tein, Tokico, etc., etc. Spend the $$$ more quality parts you'll be happy you did. I hear/see all the time about people installing some junk coilover sleeves on stock shocks thinking their car is bad ass for the 1st few weeks or months. Then they realize how shitty it actually is and re-do it properly(thats if the sleeves don't crack the shock perches).