I'm with Red Eye on this one.
It seems to me that you're having troubles gauging how difficult a feature will be, mainly because of your lack of experience with the language. Referring to the water as particles kinda gave that away.
I suggest you pick around the source a bit longer, find some easy things you could do on your own. Weapon weight sounds easy, but believe me there are much easier things you could do. Dealing with weapons means dealing with the several arrays and (massive) UDTs that go with them.
Or, you could try implementing airmod 0.6 into the newest source and as you go along, look at what the code is doing and how it's effecting the current system. It's a very good learning experience, especially if you've never touched the source before.
On that note, however, I would not expect to get it working for a while. There's a reason not many people have done it.
The one and only,