Last fall I replaced my WFCO 9855, which had died, with a Progressive Dynamics, I think 9260 (it's too early to run out in the dark and check)...I love it! ( I carried it as a spare for almost the whole season, as the WFCO was indicating it was going bad) I ran the charge wizard through the back of fuse box and can see it flashing through the fuse box window under the television...so I know what the battery is doing by the rate of flashes.
This converter would be my recommendation.