Yes, the build in the OP will work just fine, at least on Gold. Lancer is probably the best gun for that build. I also like the Indra, and the PPR would probably work quite well if you had a long duration on Reave. Also, because you're going to be stationary, the Revenant works surprisingly well with that build if you plant yourself in hard cover. With all the DR you get from your various sources, you can empty the entire clip without dying, then slip back into hard cover to reload, and your shields will be recharged by the time you want to start shooting again. One of the only setups I like for the Revenant.
I used to play the Justicar as a pure Pull-Reave setup on Gold, with the Acolyte and BPP as a sidearm for armored enemies, and it works really well that way. But lately, I have been trying the Reave-spamming DOT build, with various pistols with Power Amp and Heavy Barrel. It works shockingly well against pretty much everything except Geth, and it even does well against Geth if you bring Phasic ammo instead of Warp ammo.