There may be difference in data because....we are trying to use another utility then that exists now in production...for cost save...so we will replace all the parameters...so there may be difference...so to confirm its the same...we want to compare...
did You care to try to understand about reliability of software provided by <primary> companies ???
naturally if You go cheap such guarantees do not exist
also why not ask the new software provider about the conversions tasks... ???
Your organization is money saving mode so You thought better to get free consultancy on a forum