Worklight, I'm not sure how familiar you are with HID lights (I certainly wasn't when I first came here!), but one of their huge drawbacks is a slow startup time. Many HIDs take 10-15 seconds to reach full brightness - definitely not the sort of thing you'd immediately "fire up" to blind an intruder with. (Please don't let my 12th grade English teacher see that last sentence...). In other words, if you're going to turn the light on once, and leave it on for the next hour to search a warehouse, HIDs are great. They're extremely efficient, and perfect for that kind of extended use. But for instant-on situations, they're definitely not the best.
You might find that you'd be equally well served by a 500-1000 lumen light. Indeed, you'd be surprised at how bright 500 lumens can be. (I don't know if you've ever seen a Surefire M6 in person, but it definitely rivals my car's headlights - and that's just with 500-700 lumens.) In fact, the darker your warehouses are, the brighter each lumen will seem to be. If you can handle 500 lumens (and I'll bet you can!), you might want to consider a G&P R500, a Surefire M6 (especially with the rechargeable options using LumensFactory bulbs or JS's packs), or a Mag85/Mag ROP mod, all of which are relatively compact and easy to carry on your belt - and all of which come on at full brightness the instant you fire them up.
But if you absolutely *must* have an HID, and it *must* be belt-sized, and it *must* be 35 watts, the Microfire is the only one I can think of off the top of my head. If you want an HID that's easily carried on your belt, but would be satisifed with a light that provides 500-1500 lumens, you could consider AE Powerlight's 24 watt HIDs, or even a modified 10 watt MagHID (just smaller than a standard 2D maglight).
Best of luck finding what you need.
- FITP