I don't see a problem with upping the airflow levels a little, but since you're running on the stock bottom end, I'd suggest a retune on the dyno to make sure you're still within a safe A/F ratio and the computer is pulling enough timing and adding enough fuel where it should.
Intercoolers are great....anytime you can drop that ACT's (Air Charge Temperatures) you're both increasing horsepower making ability and safety margins. Vortech sells an Air to Water unit for your kit, but I've people are mixed about its effectiveness. On one hand, it's great for the track where you can fill the reservoir full of ice water before each run lowering the ACT’s below ambient. On the other, it suffers from "heat soak" during daily driving conditions, reducing its effectiveness and providing inconsistent temperatures.
Air to Air would be less expensive and more consistent for a daily driver, but the lowest you’ll be able to drop charge temperatures is to ambient levels (and that’s with a really efficient unit) and it won’t perform like an air to water with a tank full of ice water will at the track. That being said, if you've got a street car that rarely sees track time, then it may not be worth it to you to spend the additional money, just for a few runs at the track. The rule of thumb is to use the largest cooler you're able, in order to maximize surface area. Don't cheap out either...a well built cooler will less surface area can outperform an el-cheapo with more. My guess, is that your friends 240 cooler would likely be far too small for your needs.
Another method that's become popular is running one of the chemical systems like water/methanol in place on an intercooler/after cooler. It sprays a fine mist of water and methanol into the discharge stream, lowering charge temperatures and increasing fuel octane levels. Both of which allow you to run more timing than you could with an intercooler, which results in more power. The down side is, is that the water/methanol only lasts as long as your reservoir does, so keeping it topped up is a priority. They also haven't perfected a system that provides the user with 100% reliability, especially with the constant operation that daily abuse can present (which can get dangerous in the event that the system doesn't activate, or you run low on the mixture). Finally, long term effects of spraying water/methanol in excess has show damage to internal components due to the corrosive effects of methanol over time.
