I'm looking to build my first AR and just want to make sure the parts I'm looking to get will work.  I figured I would just buy a completed upper assembly and piece together the lower.  Here are the parts I came up with (minus optics).  The main concern I have is using the Bushmaster LPK with the Spikes stripped lower.  Would it be better to go with a Spikes LPK?  Aside from that, would all of these parts work together?  


Upper Assembly
http://www.stagarms.com/product_info.php?cPath=14_24&products_id=244

Lower Receiver
http://www.aimsurplus.com/product.aspx?item=F1STSL&name=Spike's+Tactical+AR15+Lower+Receiver&groupid=53

Lower Receiver Parts
http://www.aimsurplus.com/product.aspx?item=XBMLPK&name=Bushmaster+AR15+Lower+Parts+kit&groupid=53

Complete Buffer Kit
http://www.aimsurplus.com/product.aspx?item=XDSABK&name=DSA+Complete+Buffer+Tube+kit&groupid=143

Stock
http://www.aimsurplus.com/product.aspx?item=XMAG310Blk&name=Magpul+CTR+Carbine+Stock+M-Mil+Black&groupid=147

Should all work fine.  I prefer the older BM kits to Spikes but would think most the new stuff purchased today is tit for tat.  Haven't used a BM kit mfg'd after 2000ish. I'd personally buy the most reasonable or at least expense including shipping.  Think I'd also look hard at PSA if looking to build tomorrow.  It's yours build what you want.  All milspec should be compatible.