Hi, I'm newer than you to this forum but also own a DPMS Oracle LR-308. I've done a few things to it and will do a few more things, it's been my project rifle and entry-level into 308 ARs, kind of how my Springfield Mil Spec 1911 was my project/entry 1911.
Most of the things I think about the rifle are "general AR" items, not really particular to the 308 cartridge. I don't like GI AR triggers, prefer Geissele. I like the Magpul MOE pistol grip. I like the Magpul MS3 sling. I think castle nuts should be staked. I prefer pinned gas/front-sight blocks. I think bolt carrier groups need to be of good quality.
As for optics, gosh, the choices are endless. I have an Aimpoint H1 on a Daniel Defense mount for my red dot (Larue quick-detach mounts are probably the most popular choice for the red dots), and a Nikon Prostaff 3-9x40 for longer range (will be upgrading to a better magnified optic) on a cantilevered mount (forget the brand name). For a rear iron sight, I use a Troy but find Magpul polymer and steel rear sights good (have a polymer on my Colt 5.56, works great).
Anyway I think this DPMS model is a good starter 308 after having owned one for 2 years. I recently ordered a barrel with a pinned FSB and will swap that in as soon as it shows up at my door. Do not shoot Tula steel-cased 308 ammo (I'll discuss this more elsewhere on the forum site)! Stick with something like PMC Bronze (brass cased, good price, good track record).