Based on what I read and have personally experienced:
1) Closest to equal length
2) Stainless steel
3) Modular pipes connected to merge collector but this leads to more potential for leakage
1) Lots of real world feedback from owners on this board
2) Relatively cheap
3) Mild Steel not stainless but ceramic coated
1) Stainless Steel
2) Priced a bit above Evosport's
3) The complete RDSport headers/cats/x-pipe/exhaust were installed on the Fisker Latigo CS and it passed smog
There are also similar options from Turner (cat-delete) and RPI but I have not seen any feedback yet from them.
Wait! You didn't tell us which brand you went with!