I've read through every post so far and it seems like DPMS is getting a bad rap for some reason. There's even one post calling for "support" to back up a claim that their rifles are quality; all the while not one person who has downed them has offered any such support for their claims. If the OP is still interested here is a quick comparison of the DPMS Oracle and the Spikes Tactical ST- 15. All the information can be found on the respective websites. I've tried to stick to the pertinent stuff and filter out as much fluff as I can. Here we go.
DPMS- Forged flat top, 7075-T6 Aluminum Alloy, Mil-Spec anodized and teflon coated, shell deflector, forward assist, dust cover
Spikes- Forged flat top, 7075-T6 Aluminum Alloy, Mil-Spec anodized, Dryfilm lubed inside, forward assist, dust cover
DPMS- 16" Chrome-Moly steel, 6 grooves, 1x9RH twist, A2 flash hider
Spikes16" Chrome-Moly, 1x7RH twist, A2 flash hider
Bolt Carrier Group
DPMS- 8620 steel carrier/bolt, heat treated, Mil-Spec plating
Spikes- 8620 steel carrier/bolt, Mil-Spec phosphate finish
DPMS- Forged 7075-T6 aluminum alloy, aluminum trigger guard/mag release, Mil-Spec anodized
Spikes- Forged 7075-T6 aluminum alloy, Mil-Spec anodized
As you can see both rifles a very similar. The only difference between the two is the warranty; DPMS only runs for 3yrs from DOP where as Spikes is for life.
HOWEVER, it should be noted that all the parts required to assemble a rifle from one of the other manufacturers (DD) can be purchase for about $750 on Midwayusa.com and you could probably find a gunsmith(the place you have the parts shipped perhaps) that would be willing to put it all together for you for a small fee.