I'm choosing between two upper/barrel one, Two
Lower
With the lower i'm not sold. I like Magpul, but I kinda want to build my own, also I'd like a nice trigger, and will probably change out the stock. Is the trigger included in this quality? or would you still recommend building my own?
For reference Stock I really like
CH, BCG, Flip up sights

Am I missing anything? Would you recommend changing anything?

thanks for any help!

I would build your lower how u want it get the trigger and stock u like.  The lower that u linked will likely have a standard mil spec type trigger in it.  Get one of the uppers u like to slap on.  Never used the fail safe bcg but i'm sure its fine and so is that charging handle.  The flip up sights seem nice also.  If u build get one of the psa lpk w/o fire control group and a buffer spring and buffer.

I would recommend the aero precision flip sights over the fab defense. Trust me on this, after you handle a fab d product they just seem cheap.

$150 for a complete magpie lower aint bad, but moe is the cheapest of their product line on a blemish lower none the less.

The MFT minimalist stock, while inexpensive, has become one of my favorites. Both for looks, and fit. That magpie UBR is very neat but she's a pig, and the more you look at it, the more you see good ammo money wasted. That was my experience anyway. Good luck to you.