I usually reccomend neuspeed sport springs, but you want stiffer, so I'd use the race springs, especially with the added weight of that motor. Those will lower your car 2.25" all the way around, which is plenty low for a honda. 3.5" is way too low, you would hardly have any suspension travel left and you would bounce/bang/bottom the suspension all the time. No fun. As far as struts, I've used KYB AGXs in the past and have loved them, they are adjustable, so you can dial them in as firm as you want.