I just did this two days ago. At the suggestion of Redog and johny boy 32 (I think it was them) I got the Silverstar 880's. The only difference is that the 894 has a angle plug and the 880 is a straight plug. But there's plenty of room down there, so that's not an issue. The 894 plug has the clips on the side and the 880 has one on the middle, on only one side (like the 9006), so the plug isn't "clipped" into the light as secure as the 894 would be. Of course, I had some rubber-coated wire ties laying around, so I just wrapped that around there a couple of times. It's not going anywhere unless I want it to.
A while ago, I had replaced the 37.5 watt stock 894's with 55 watt 894's. When I put in the Silverstars this week, I changed the low-beam and the foglight on one side and then turned 'em on to compare. The headlight is totally brighter and whiter, but the 29.5 watt foglight doesn't look much different than my 55 watt regular ol' foglight bulb. At least not different enough to justify the price. That's alright though, I'd rather use that extra current for other toys...
Earlier today, I was driving behind a Volvo with HID lights. Oooohhhh, I want that...but I'm not looking to do another $400 mod right now...