Oh, also - have a clear picture / vision for what you want this to be. You mentioned target gun, which is a great start, but will this be shorter range or longer range? Do you care if you weigh it down with whiz-bang gizmos like lasers and flashlights? Will those actually enhance the experience, or do you just want it to "look" cool?

In other words, the attachments you buy should not be random, but rather support your overall goal and vision for your AR.

For example, I wanted to keep mine as a fairly light weight range fun gun, so I didn't want to add an aluminum quad rail. I didn't need the slight increase in accuracy, since it's not a competition gun, so I didn't need to free-float the barrel. I wanted to be able to comfortably support it for longer-range (to me, anyway!) target shooting (100-200 yards), so I added a bipod. Mine came with a cheapy red dot, which I liked (and my wife really likes), so I wanted a more reliable and proven one.

Have a goal. Again, shooting it at the range, in the field or in the woods (safely and legally!) will help you land on a vision for what you would like to have.