CRJ-900 Captain reported executing a go-around after encountering possible wind shear and wake turbulence on approach to JFK from a preceding heavy jet.

Narrative

Descent into JFK; runway change at 10;000 ft. from 4R to 4L. ATC kept us high and fast to get us spaced in behind a heavy. I never caught what kind of plane it was. We were eventually cleared the approach after a late vector where we overshot the runway. Eventually the airplane caught back up; but we were still doing 250 kt. 10-mile final since that is the speed needed. Once cleared for the approach; I went full spoilers to slow us down; the airplane struggled to get below 230 kt.; and eventually went down to 225 kt. That is when I called for flaps 8. From there; the airplane jumped back up to 230 - 232 kt. and the flap overspeed clacker went off. I clicked off the autopilot to slow us down by pitching up a little. I then turned the autopilot back on and the plane slowed. We then hit major wake turbulence and I clicked the autopilot back off and called the go-around; this was at approximately 1400 ft. The airplane entered a large bank and the most noticeable thing was the windshield wiper being forced into the middle of the windscreen; it then returned to its position quickly. The go-around was uneventful and we came back around to Runway 4R for an on time arrival. Cause: Likely unstable approach and wake turbulence encounter with likely windshear. Suggestions: When potential wake turbulence or windshear encounters arise; give a good buffer below speed to call for flaps.