The type of antenna for the Intel® Dual Band Wireless-AC 7260 7260NGW is defined by WiFi 802.11ac standards determined by the WiFi Alliance.
You can find more information about the specifications of the Intel® Dual Band Wireless-AC 7260 in the Product Brief.
We would like to mention that this adapter is meant to be installed by the computer manufacturer or its authorized representative. Installing or upgrading the various Intel wireless adapters by end users is not supported by Intel.
Regulatory requirements must be met by the computer manufacturer to determine if the Intel wireless adapter can be installed in your system.
The link you provided appears to be for an Antenna modification Kit for wireless routers and access points and may not be suited for use in PC's.
If you are making a custom integration, we advise you to check with the PC manufacturer to know if the Intel® Dual Band Wireless-AC 7260 7260NGW is supported in your system, and the type of antenna required this configuration.