Both are great events. Summit is a bit more newbie friendly over all trails wise and you will find a larger concentration of FJC's. ALL Toyota events these days have a good number of FJC's but the Summit is the most concentrated.
As for getting into 2017 - that's yet to be announced how they are going to do registration next year, if it will change. Worth trying to get into.
Also open up your options for events too. The TLCA
EVENTS | TLCA Is the Toyota Landcruiser Association, there are events held accross the US sanctioned by them.
In your area in PA comming up in a week is the 2016 Coal Miner Cruiser Classic.
Coal Mine Cruiser Classic - Gotham City Land Cruisers
I personaly have not been to the Classic yet, but we (Metal-tech 4x4) have sponsored the event for years and hear nothing but great things about it.
My personal all time favorite is the Southern Cruiser Crawl in AR.
Annual Off-Road Event | CottonLand Cruisers
Regardless of where you go, do GO! Events are a great way to learn more, meet great people and flat out have a great time.
Mark