I put these on the stock heatsink with some thermal adhesive and the temps dropped dramatically with no movement from moving the case around.
CASE FAN, 40X40X10MM, BALL BEARING, 3-PIN https://www.amazon.com/dp/B002OFL1J8/ref=cm_sw_r_cp_apa_dTJJAb43ERZW4
CASE FAN, 40X40X10MM, BALL BEARING, 3-PIN https://www.amazon.com/dp/B002OFL1J8/ref=cm_sw_r_cp_apa_dTJJAb43ERZW4