use VNAV
If I were doing this I would put 5000 as a "hard" altitude at KELON and go direct to the fix. Ensure LNAV is the active mode, set the MCP alt to DA and arm VNAV. I would then get a TOD at about 5 miles from the fix (approx 3000 ft to loose from FL80) which would be well within the MSA 25.
I would allow LNAV/VNAV to make the turn to final and since you have DA in the MCP, VNAV will cross the IAF (KELON)at 5000ft but in a descent allowing you to arm the approach and get a LOC and G/P capture.
I don't have the chart so I don't know the distance between the IAF and the FAF. Depending on that, VNAV may well level you at 5000 until you reach the G/S outside the FAF.
And NO you are not capturing the G/S from above you are capturing it further out but from below.