B&C New Briefs Æ Wondering if that pool of subprime mortgages you plan to bid on is all that it’s advertised to be? Officials at technology vendor ARC Systems say they have a way to find out. Later this month, ARC plans to take the wraps off of its Loantech Investor system, a technology platform designed to help investors get a better handle, both before and after they bid, on the composition of mortgage collateral