Would WAIT on LR until SG is up to par. Lets not kill off Any inverts that maybe on/in the LR. Such dieing off will/can foul up water which may pose problems to your existing fish.
sump or Not?
If sump is not avail,
HOB Skimmer but before purchasing, think of running Sump (recommend) thus eliminate possibility of spending money twice (maybe).
If sump is definitely out of question, should run skimmer ASAP since your SG is at 1.016. It may not skim as well as at 1.022 but should skim pretty well at present SG.
I dont have any recommendation since all of my Venturi skimmers were
DIY except one on 20G. It's Seaclone but would not run on 80G eventhough they claim it can.
Hope this helped.