If you have the AK body for your drg, don't worry about the dl body yet, though as a drg you may want some darklight before attempting titan anyway. Bombs can get dangerously close to one shotting you, so you may want the gear to survive an accidental bomb you didn't avoid in time. If you can win before getting any darklight gear at all, I'd say Gae Bolg would take priority, then dl armor as you desire starting with your lowest end pieces, then accessories. The Gae Bolg is 3 damage higher than then next best spear you can have which is garuda or titan's or the HQ Obelisk, and has better stats than any of the 3, so it's definitely worthwhile in pure damage,and given that you're a drg damage is imperative. Doing terribly basic eyeball math, I've seen that 30 strength is about a 10% damage increase, so keep that in mind when selecting gear upgrades (though this observation was made on warrior, and doesn't take determination into account).
I'm actually stuck with a hard choice to make right now. I still am working on my war for gear and such,but now that my drg is nearly full DL and has a Gae Bolg, idk if I should +1 it yet, or continue buying myth upgrades for my war. Really a hard decision :(