Latest update. I had to bite the bullet and buy the OEM catalytic converter, given that Bosal has told RockAuto.com, as well as myself that the bolt patterns to their direct fit CATs won't line up with the offset bolt pattern on a VX exhaust manifold.
In fact, RockAuto had mentioned that four other people have returned Bosal's direct fit catalytic converter due to this issue. To their credit, I am grateful to say that RockAuto has refunded me in full.
The moral of the story ,is that unless you're able to see an illustration of the bolt patter from an aftermarket CAT, it would appear that the OEM catalytic converter is the only way go.
. The upside however, is that the substrates used in most aftermarket catalytic converters are guaranteed for up to 25,000 miles. The OEM CAT should last forever.