Rossi's are used alot in CAS & there are smiths out there that can make them sing...
It hurts me to say this, but today... there really isn't a lever being made by any of the companies ( except maybe Henry ) that spends more than 30 seconds checking out the quality of their rifles... if you are buying new... it's really anybodys guess... Marlins used to be some of the best... Winchesters were good, but you were often paying for the name... Marlin is reportedly having QC issues right now, that is serious enough I wouldn't buy one that's been made in the last several years...
on the other hand, reportedly the Rossi / Braztech / Tauri have been getting better... still my one of my buddies just bought a Rossi last year, & my gun smith buddy that fixed it said it looked like they put a 44 extractor in his 38 rifle...
I almost recommend contacting some of the companies that sell & tune Cowboy action levers... new or used, it would insure you got a gun that will function...
my wife will be starting CAS next year, & will be using my 20 something year old Rossi 38 / 357 that works like a dream... so I'm in the market for a new lever myself... I think I'm buying a stainless Rossi in 45 Colt for me to use next year