Definately make sure that all maintanance is up to date BEFORE ANYTHING ELSE. After that, keep going with suspension. You got better wheels on it already. Now go for drop. If you don't want to go to low, and you on a budget and cant go for coilovers, get eibach prokit springs and some good shocks.
As for engine. cold air intake, cat back exhaust, better wires, better plugs, upgrade the coil. Headers might not be needed, depends how far you plan on taking the engine. Make sure all your sensors are in good shape. Picking up a service manual will tell you how to check your sensors. A sensor that is on it's way to go bad might make the car run different. Also look into giving the engine a good clean. read this thread.

https://www.honda-acura.net/forums/s...d.php?t=175118

It will definately make a difference. Plus it's only about 4 bucks for a bottle, and about 1.50 for some cheap plugs. If the o2 sensor has never been changed before, this cleaning might finish killing it though, so prepare for that.