Short answer is, yes, I believe you could do this with any of a number off-the-shelf SaaS offerings. A lot of it depends on what you are trying to accomplish to determine if that suits the requirement. Some companies build entire ecosystems (and ancillary affiliate/referral revenues) from building other tools into their supported "stack." I've also seen companies invest in doing their own "home grown" PM systems for this type of vertical integration such that they control the entire system end to end.

I'd be happy to run a pros/cons with you if that's of assistance.