I installed a Optima Red in my car this season. Works great especially with the stereo upgrades I did earlier this year.
Optima's are priced a liitle higher than normal, but I have been using this batteries in cars with high current consumption (Not our NSX for sure!) applications such as stereos and hydros etc.
Optima is a very efficient, 360 degrees mounting, almost vibration resistant, and best of all deep cycle with fast rechage. The Red has higher AMP meant for cranking and light loads and not meant to be rechaged frequently, and the Yellow a little less crank PWR but lots more current of longer amounts of time. (Like your gonna need this anyway for an NSX)
This only thing I had to do is switch the Neg and Positive from left to right if your facing the front of the car. OEM has the terminals reversed form a standard battery and the terminals on a replacement would be closer to the middle of the battery.
I will trade my Optima Red to a Yellow before the end of the year. That way I'm able to leave the stereo on all day long without worring of battery run down. I still have my original Yellow top going 6years strong in my other car.
Dali also sells the Odyssey Dry Cell $100US and alot smaller than stock which will require a special mount to be made or bought. I haven't used one of these but seems to be a very good battery as well.
Hope this helps...