to be honest I havent dealt with that stuff.. although i do have a broxa MP5 and a TSD VSR clone I mainly use my CA, TM and RS..I was once your age when i was getting into airsoft, i was 15 when I started so i know exactly how you are feeling right now. That gun you wanted to get off of buyairsoft was a grand and it is NOT worth it.
My advice to you is to save your money untill you are 18 then get avd and flip though the classifieds then looking for something nice. The reason i recommend u to save your money is because you will need to buy a gear loadout, mags, radio, mask/goggles. It all really adds up very fast. Also those few years will allow you to ask questions and do research before you make a BIG investment in an AEG. I know i made a mistake when I got into airsoft and i would do a lot different If i could do it over because i got ripped off
A great starter weapon in my opinion is would be a full metal ICS or CA armalite series. Have a look into those
again, ASC is a wealth of knowledge, look in the discussion sections for threads on weapons and gear, if you read up you can discover and learn from other peoples mistakes.
The experienced players on ASC are usually more than happy to answer your questions but make sure you look around to see that someone else hasnt already answered your question in another thread because that is a one way trip to getting flamed...
If you want you can PM me with some questions if you need to, I've been in your situation before so I know what your feeling