The Rock River 2-stage triggers are by far one of our best selling triggers and lower parts kit. We sell by far more of them than ALL the other basic LPK's combined.
Some people like a lighter trigger pull. You can drop the JP reduced power springs in them AND the battle triggers to give a lighter trigger pull. The RRA 2-Stage will be ~4.5lb with both stages combined with stock springs. With the reduced power springs they'll be ~3lb-ish. The stock Spike's Battle Triggers (& Enhanced LPK's) will be ~6lb pull with stock springs. The nickle boron is very smooth. We've been throwing together a custom AR pistol lower this weekend for a personal project with a 300BLK pistol barrel we chambered. It has the Spike's Battle Trigger in it
http://www.joeboboutfitters.com/product_p/brn-452-000-007.htmThat 12" BAR upper is a good deal! These fly off the shelf when we get them in stock and it doesn't seem many retailers carry them for whatever reason. They're probably my favorite Spike's upper.
The stock/buffer you could probably do much better for your money. We sell a generic branded one (UTG) for $55 out the door. 6pos milspec tube and works great.
https://www.joeboboutfitters.com/ProductDetails.asp?ProductCode=UTG-RB-T6BMAny of the cheapie plastic stocks are going to be the same quality, really. I'd grab one with a milspec tube if you can so you have more options later on if you want to upgrade to a nicer Magpul, VLTOR, etc stock.
Also, the Spike's T2 buffers are very popular with their tungsten powder. We sell by far more of them than the standard buffers.
We've been getting a boatload of some backordered Spike's accessories purchase orders in as of recently. We've got a lot of the battle triggers, enhanced LPK's, and T2 buffers hitting us tomorrow and Tuesday.
Edit:
stesch_s10-Nice looking black GSD in your avatar. I have an all white Shepherd. Great dogs!