I would think any stereo shop should have it. I got my from my local shop. If your local shop don't have it, let me know and if you want I'll ask my shop to order you one (I'm in OC). I think the price was something like $80-$100. The unit is also known as game port.

I found this on the web. http://www.audiooutfitter.com/store/74450/IN501K.html

 

There are the pics of mine. PS2 in glove box wireless remote and power inverter switch moved to panel next to steering wheel. The power inverter is inside the passenger side kick panel.

 

just so you know....the slimline can be powered 12 volt.
just check ebay
im waiting for mine to get here.