I would say go with the SS. That way, if you bump up to 190 injectors or something, you will still have enough turbo. With that SR, I doubt you would be satisfied if you ever upgraded injectors. Just my 2 cents...
I don't have any plans on upgrading my injectors. I tow heavy and use the truck as my daily driver/hunting and towing truck. I am trying to make the truck more efficient. Would I be better served by upgrading the intercooler or finding a more efficient turbo?
I have an Elite VGT-SS with stock injectors currently. I don't tow, so I couldn't tell you what the towing performance is like, but I am very happy with the turbo. I would think that an upgraded intercooler would help keep your egt's down for less money than a bigger turbo.