I've seen a couple of post requiring data to be imported into GP but needs to be QA'ed. Example, let's say you have an e-Commerce system where orders get created and are manually entered in GP as Sales Orders. While entering in GP, the user make changes to amounts, quantities, prices, costs,etc.
Over the years, Microsoft Dynamics had been creating tools to make integration easier to manage. You can create interfaces using GP Web Services and this can reside outside GP where you can QA data before the actual import happens. The advantage? You're not using any GP license.
Another tool you can use - eConnect. A lot of GP vendors have created eConnect templates for ease-of-use and faster ROI.
You can also look at SQL Server Integration Services. This improved version of DTS is a true ETL solution for enterprises.
My 2 cents, spend more time choosing the right tool as each can have their pros and cons. Also consider creating a Staging database when you're not sure if data is reliable enough to be imported to GP.