Stag is good to go. If you're set on buying an already complete lower, Spikes Tactical has a complete lower including a stock and buffer tube assembly for just $50 more. http://www.spikestactical.com/z/inde...products_id=86

Their lowers alone are only $90 and LPK's are $65. If you do decide that you want to assemble it yourself (very easy, and fun if you're a tinkerer) that right there will save you close to $50 and get you the same thing the Stag provide.