project management integration

We have a small team and I wanted to look at using either the inbuilt project management in FS or an external one like Wrike. and have the Tasks that get created in the PM tool sent across AS service request. Enabling the team to work from one product and myself managing the project. I see that you can have task in FS but this mean the team have to keep flipping out of the queues. Any ideal would be great thanks