I'll admit to only knowing what is reported in the public realm but here goes. I'll guess the Israelis will want to export their F-35 addons to any other F-35 interested users.
Israel To Buy F-35s With Cockpit Mods 27 Aug 2010 by Alon Ben-David (AvWeek Story originally)
http://list.freeman.org/pipermail/freemanlist2/2010-August/013664.html
"..."The aircraft will be designated F-35I, as there will be unique Israeli features installed in them," a senior Israel air force official tells Aviation Week.
Israel's initial batch will be almost identical to the international JSF offered to other countries, with one difference: The F-35s manufactured for Israel will include several cockpit interfaces to accommodate the air force's command, control, communications, computer and intelligence systems. The F-35 main computer will enable a plug-and-play feature for Israeli equipment...."
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Israel, U.S. Agree To $450 Million In F-35 EW Work 06 Aug 2012 By Eshel David, David Fulghum
Source: Aviation Week & Space Technology
http://www.aviationweek.com/Article.aspx?id=/article-xml/AW_08_06_2012_p28-482027.xml&p=1
"...In the F-35, all core avionics are integrated and fused; therefore, accessing part of the system requires integration with all associated systems. Having different air forces using different versions of core avionics would render such integration more complex and costly.
The avionic architecture of the F-35 solved this by introducing two separate integration levels. Customers can access the high level, introducing country-specific services, libraries or updates on their own, outside the aircraft software-upgrade cycles. The lower level is proprietary to the U.S. Joint Program Office and accessible only by Lockheed Martin. This level manages flight and mission-critical services, including flight controls, CNI and display, sensor management and self-protection. It also relates to the sensitive low-observable envelope of the F-35, an issue passionately guarded by the U.S.
Replacing core avionics with new systems at such a profound level of integration is unlikely, as it would require extensive testing by all F-35 operators with no obvious gain for the developer. The IAF is moving toward a different approach—the implementation of so-called integrated modular avionics (IMA). The concept has been in development under an Israeli Defense Research and Development Directorate program for several years and is currently being implemented under several pilot programs.
The architecture employs three layers for the integration of new applications—unified hardware, comprising a powerful general-purpose processor (GPP) and large memory bank, and a library of devices and services made available to developers, similar to a software developer kit...."