Yep, when it comes to wire your budget is the only factor on how big to go beyond the "minimum"... I've also noticed a lot of cheap car audio wire that appears to be at least 2 gauges smaller than advertised (It's been trending this way in cheap brands for at least the past 10 years). The increased strand count is for increased flexibility to route around car interiors. Not really an issue with cubs and that finer strand count also costs more money, and yes, the finer individual strands are more likely to break.
I have bought A LOT of wire and terminals from this guy on ebay. I'm not affiliated with him any way, just a loyal and satisfied customer. All of his wire is UL, SAE, and Coast Guard approved Marine Grade. The last time I bought from him I messaged him a parts list and asked for a discount, which he was happy to provide.. It was about 15% off. Anyhow, check him out!
http://myworld.ebay.com/genuinedealz...p2047675.l2559
His 8ga is an honest 8ga and is reflective of what IH put on both of my cubs. 8ga is good to 200A at 7' length (longer than a cub from nose to butt). 6, 4, 2, 0, 00, etc won't hurt anything. I'd run 4ga if I were to rewire one from scratch, which would be massive overkill. His prices are good and his product is excellent. I have his 2/0, terminals, and wire boots on my Mustang charging system right now (200A alternator) and my Dad has his jacketed double 8ga running out to the front of his loader on his Deere. No problems!