I have the Corsa in stock, but I will not sell HF RT cats, don't trust them or think they are worth the trouble IMHO.
There have been failures and melted cats, The stock ones hold up much better in my mind and unless you run no cats you are talking about 2-4 hp. If your cats are all bad though you may not have a choice that is cheaper than the RT solution. Maybe someone on here has an old take off set they would sell you cheaper?
I hate to say Phooey on a fellow, respected vendor, but
PHOOEY.
RT Cats are made in USA, have a 5-year written warrantee, and the warrantee history is an open book. We have thousands of these installed on Vipers since 1999.....and
fewer than 10 warrantee claims in that time. One customer had TWO claims, and his tuner says it was 'other issues' that caused the failure. RT treats each rare claim generously and objectively, and PartsRack makes sure they do! Not a battle.
Random tech cats include an extra, custom, "wash" of the costly substrate coating that ensures they pass CA, and last 5 years. They quote guaranteed flow rates in CFM, and are proud to place their NAME proudly on the cat. Several tuners buy these with regularity, as does a major exhaust manufacturer.
We used to carry the cheaper, un-named brand, with its higher profit margin, and we still could. We stand behind, prefer, and recommend RANDOM TECH Cats for several reasons as above.
When considering a cat, KNOW what "brand" you are actually buying, where it is made, its flow rate, and its warrantee. All in writing, not just verbally. You will do well to choose Random Tech.