I'm sorry I saw this so late. Not to rub salt in an open wound, but that's exactly what I was talking about in my build thread, and why I brought it up-they don't fit, and won't fit no matter how you try. Sorry you had to find out the hard way.
If you still want spacers, get ahold of Jeremy at JT's-he's just down the road from me in Cashmere WA, has plenty in stock and is great to work with. Standard Jeep TJ 5x4.5 pattern that will fit your standard Dexter hub pattern and the center bore is plenty large enough to fit over the Dexter hub drum, even with electric brakes like I have on mine. Here's his site:
http://www.justdifferentials.com/index.php?main_page=product_info&cPath=467&products_id=2163
I'm not sure I linked the exact spacer there-he has several different ones, including cruisers and 8 lug chevs. For the Jeeps, which will fit the Dexter axles, he has 1.25", 1.5" and 2" to buy the clearance you may need to get it out away from the frame more which will help with your cutting/welding you're after now. Check my build thread for more info, I don't remember the specifics. Haven't updated it in a while as I've been working so much. I'm off now for two weeks of elk hunting and wheeling so no trailer work for a while yet. Oh, these are a bit cheaper than Spydertrax too. For what it's worth, I have over 30,000 on my Spydertrax on the Jeep with great results. I'd have used them if they would have fit, but as you found out, they just won't work. Jeremy's will, and do. They're a great alternative.
Best of Luck,
Mike