Data Integrity Check / Migration Between 2 CRMs

We have a CRM that we pay access to house our client informations. Notes, Leads, Payment Information, Payment Schedules, Statuses, Call Information. There is about 15-20 CSV files that we can export from that CRM. As of now, we have our own in house custom built CRM that will need to house all of that information. We did an import into the system, and we think we got almost everything, but just in case, we need a data integrity check on everything. We still need our notes and call information imported. This is essentially a CSV to MYSQL migration/check job. Most importantly our payment schedules need to be correct with the right process dates, and attached to the right client (also making sure the client exists in our system). This is important because all of our clients are being charged on a schedule they are set to. I need payments schedules to be correct in our system so we can seamlessly continue with out payment system in our CRM. Our CRM's database is different from the CRM we are leaving, so its not an easy 1:1 migration. Certain information is broken up into different tables and spread out. It is also needed to be done as soon as possible since our payment schedules can't be out of sync. Also, this is very sensitive information we are dealing with, so we have to have complete trust in our hire. We are looking to spend no more than $800 for this job if it done completely and right. We would like someone who can possibly chat through skype.