AEM UEGO. It's a standalone wideband gauge with the sensor and it's very accurate...same one I have. You don't plug it into any computers or calibrate anything. Mount the gauge, hook up the power wires, plug the sensor into the downpipe and go. Here's the link to AEM for all the info:
http://www.aempower.com/ViewCategory.aspx?CategoryID=67
They come with the different color faces and bezels so you can put on whatever color you want to match your interior. Check eBay, you can get them cheaper than directly from AEM.
You'll hit 300whp easy with your build and a good tune. You have an auto transmission right? You should at least get a full fluid flush and run an exterior cooler for that much power, plus a B&M Shiftplus...but maybe you already have that planned. Keep us updated.