ARP Bolt Kits
My ARP mopar kit was a total mess too. Front cover bolts and water pump bolts were not correct. I only got about half the oil pan bolts. They suck.
Though I havent ordered a Mopar engine kit from the outfit below, I have had great luck with these guys on other projects:
http://www.totallystainless.com/
As far as the strength of stainless bolts, here you go
http://www.totallystainless.com/yoursafety.htm
Steve