So, I have 250$ from selling some items from home, and decided I need more upgrades on my Echo 1 ST6 DEVGRU. I already have a Magpul AFG,MBUS sights and a PTW clone crane stock. I am thinking internal and extrenal upgrades, but for external, the most I'm thinking about is an ACOG 1x32 or MGO and a PEQ. For internals....I have no idea. I have experience playing, but internally, I've been running stock.(laugh at my noobliness) I'm worried that with internals, I'll end up breaking my hop-up or frying my gearbox. So, please help me out here. What parts should I get for my gun, and should I attempt to put them in myself, or find someone who can do it for me(If you know anyone...please state them.) Have a good day!