zuperman 370

I'm currently running an amuse stti exhaust, it's not a full cat back system, it's just a single mid pipe that connects to either the stock y pipe or an aftermarket one, so I was wondering which would be a better choice the tanabe or motordyne, and motordyne have 2 kinds of y pipes on their site what's the difference between the 2? And last but not least different y pipes have different measurements will these 2 y pipes I mentioned fit with my amuse exhaust, if any of you guys have anymore suggestions to any other y pipe please chime in