Yeah, those cards look familiar now that you've described them.
Yes, I would have taken a shot with the double, but this is a perfect spot to use "Ken's Quandary". (I wrote this whole response, and then realized that you can't double for less at Global, since you just click the 'Double' button. Oh well, it's a nice post anyway.

At Global, I would have doubled anyway. It's your best chance at taking first place, and there's little downside risk as you note.)
Consider what happens if you double for the full $40.
If you bust, Selecticom stands and is a lock for first place.
If you make a stiff, Selecticom splits and doesn't hit a busting hand. Again, he's a lock for first place.
If you make a hand of 17-21, he still should split and hope for good cards. He shouldn't hit a stiff though, because if the dealer busts with a 6 up, he wins anyway.
Now consider a better alternative: You should double for less, for any amount between $2 and $38. If you bust, you're still toast. But, if you make a stiff, you now force Selecticom to make a choice. Since he's not allowed to 'split for less', he risks a lot more by splitting now. He gives back the low to you if he splits. If he splits and the dealer beats the whole table, you get first place.