As for your question regarding the creation of an outdoor oriented environment, such as a jungle, the first thing that came to my mind that you might like to check out is
Model Pack 29, you could definitely create a cool game styled after Far Cry if you put some work into it.
Now, as mentioned previously, no you can't make something with quality like those commercial games, however you still can develop a very fun, original and entertaining game with FPSC, with many of it's packs and models available (check out the GC Store, built into FPSC versions 1.09 and up), and imagination too of course. It's all about creativity and seeing what you can accomplish.
Whenever you do buy something, whether it's a model pack, or a few pieces of media off the store, remember it's just like FPSC itself, so you don't have to pay royalties on using the models and so forth. Essentially, buying them is like paying the royalty for using them forevermore. Just don't claim them as your own, or try and re-sell them obviously
Mods, which are just as Vent described, would help you further in creating your game. If you're going for that jungle type game, you'll definitely want to check out a mod that increases your
fps rate; that is how many frames per second you're getting during gameplay, the higher fps you have, the less laggy and choppy the gameplay will be. Things that can cause lag in-game are instances such as having a
huge map, having too many models, characters, etc. Mods for FPSC such as
Fenix Mod, can help give you a better fps rate. Thus, you have the luxury of creating that larger map, populated with more entities and characters. Still, you don't exactly want to go over board.
After playing around with FPSC for a while, you'll get a hang of what it can handle, what your essential limitations are, and so forth. Although, even if you
suspect something is a limitation, always just make sure; experiment, get creative, because most things generally
are possible.
Hope you have fun man, and don't forget to check out great sites like
fpsFREE and
fps-files for a plethora of free and useful media.
Cheers
Life would be much easier if I had the source code.