Whatever size you decide make sure that's the size you use throughout the whole system. I personally recommend 2.5", but if you're staying with the stock CT-26 you could probably get away with smaller.
I am currently getting a set of 2.5" hard pipes made by a shop in Houston, TX. Not too far from you Dust.
The pipes they are making me are mild steel 2.5" welded and mandrel bent all the way from the throttle body, through the fender to the IC and then from the IC to the turbo. They will come with couplers and T bolt clamps. I'll make a post with pictures when they are finished. If you like the looks of them maybe you can bring your car to Houston for a few days and have them make a set for you.
A friend of mine's brother works there, and they appear to do really good work. However, this is the first time they will have actually done any work for me. I plan on taking a bunch of pictures and making a post about the quality of the job when its done.
I won't post a price on here, but I will say it is very competitive.