Edge-mount SMA connector for ~100mil board thickness
There are a couple of styles of SMA edge-launch connector that are very flexible about board thickness.

This type was I believe originated by Southwest Microwave, but is now available from a couple other vendors:



This type originated with Rosenberger:



But either of these types has lots of parts so it will be very high priced for a 3 GHz application.

Why not just use the old standard through-hole right-angle type?



The pins are typically a bit over 100 mils, so you shouldn't have trouble soldering them. For best signal integrity, mount this type on the opposite side of the board from where your signals are routed.