There is nothing wrong with SOHC engines... You should thank Honda because it is saving you money because it costs less to produce. The only drawback is that it typically can't rev as high as a DOHC engine. This is why most SOHC engines are designed to produce more torque and make their power at lower RPM's. Hell my beater F22 makes as much torque as the beloved H22, just not quite as much power because it can't rev as high (hp is a function of engine speed in case you forgot). And hey my CL has a SOHC and it sure as hell isn't slow!

Make sure to buy a COLD-AIR-INTAKE. Common gains for a short ram are 5-9hp & 3-5ft.lbs. COLD-AIR intakes produce 19-20hp & ~5 ft-lbs. (data from May 2003 Import Tuner on an RSX-S). Oh and don't waste your money on the spacer. I had mine bored out for cheap and THAT made a difference.