3T makes stems up to 150. I have an older 17 degree one and a newer Apto in 6 degree. I don't like the reverse threaded faceplate on the Apto, but it has two bolts at the steertube, whereas the older 17 degree only has one. The older one was purchased used from a friend, whom I think got it off eBay.
The weird thing is, you cannot seem to find 3T stems greater than 130 in the US. I had to order the Aptos from Europe - I think I went through Wiggle. They were cheap when I got them, like $40 a piece. (I also ordered a 140 and a few pairs of cleats to get free shipping.)
Zipp offers a 140 in one of its aluminum versions.
As for 3T vs Thomson, I am a big fan of the X4 stems. They have tested to be the third stiffest option after the Pro Sprint and Zipp. But they are much cheaper and come in more sizes, angles. So far, the 3T Apto is stiff enough. I haven't noticed any major issues with it.
Velobike NZ also has a 150 stem. I'm not sure how stiff it is. I'm probably going to switch to the Velobike sprint bars once they are available. They are quite long, and very shallow.