Access / SQL Server or Filemaker from Paradox?

I've been programming in Paradox since DOS, but one mail-order database is getting rather large (100K client records, and associated orders, etc).

Our client wants us to move to Filemaker. In fact he'd like to have a 3rd party write the programme and me maintain it. The current package has been written & maintained by myself, with an awful lot lot going on in the Object PAL code.

I already have a copy (legal) of SQL Server & 10 licences for Access, and think that's a better option to re-develop in (although I could do with some training in both).

What are the pros & cons for each app, and what would people recommend. I'm going to cross-post into Access, Paradox & Filemaker forums to get an equal view.

Thanks

MarkIf he wants an efficient, robust, scalable solution than develop the database in SQL Server. Use MS Access as front-end for the time being, but you will eventually want to migrate to other interfaces.