So, this is the one we use in our test fixtures (as they have pogo pins under them) - this leaves >3mm under the module: NASE0-S6701-TS64
AllLink M2 connector NXSE0-S67XX-XX64X_CA (2016-07-13).pdf (348.2 KB)
@akmandala knows the PN for the right standoff; I think All-link also sell this. They can send you samples, I believe.