"Ok, but isn't distortion good..."
No. And if you disagree, then, like Mr. Bostonbean, I'm afraid I can't really help you.
Here are the measurements for the TR-1:http://www.hometheatershack.com/foru...-tr-1-new.html
These are very poor measured results.
Here are the results for your SVS Sub:http://www.hometheatershack.com/foru...-db12-2-a.html
These are very respectable results.
If you want a higher crossover point than consider:http://www.hometheatershack.com/foru...-2nd-unit.html
I can't recommend the TR-1 based on it's measured results. Like I said, I'd give your SVS a try, first. If it doesn't provide enough distortion and compression for your liking then get the Gallo sub and enjoy. Can't argue that the Gallo kit looks much better than the SVS fare. That is a consideration/trade-off only you can make.