The SLR 680 and the 690 both have manual focus option in addition to the sonar (AFAIK, the earlier sonar SX-70 models do as well). These are the final evolution of the SX-70 -- in addition to the sonar module, they have an electronic flash mounted atop that, but are otherwise laid out identically and mechanically very similar to the original SX-70. Don't know if they have split-image focusing; I've never handled one, but they are made to be used with manual focus for situations (like shooting through glass) where the sonar will focus incorrectly.
Look to spend around US$150 plus shipping for an SLR 680 or 690; they're plentiful on eBay, but apparently quite popular.