So I've been thinking of buying/building an AR even though I have no idea what I'm doing. I'd want something similar in length to the pic below to be used for just shooting at the range. I'd want quality and reliability but not something that would break the bank. I'd also need to buy stuff like an Eotech, pmag, grip, etc so that'd need to be factored in as well. Can someone lead me in the right direction?