The old "YGWYPF" doesn't apply to intercoolers, in my experience. Get an ebay one that fits, from a reputable seller with lots of feedback, and rock it.
For 300whp, you won't need a big one, and even if you don't find a black one, you can paint a silver one with radiator paint.
Yeah, yeah, I hear everyone already freaking out "OMG don't paint an intercooler WTFBBQ!" Shut it. He's not building a 1200whp Godzilla. Paint isn't going to affect it one bit.
Save some money:
http://www.ebay.com/itm/27-X5-5-X2-5-AL ... 27&vxp=mtr
Keep us posted!