The Sony 28-135 F/4 is very similar to the 18-110 F/4 (video oriented with servo zoom) but covers the fullframe sensor. But if space is a real constraint, you might also consider getting an APS-C camera for video.
If you really want to use that lens for video, then just pick up something like the 24-105 for stills and carry a second lens. It's fairly compact and is fairly close to the same range you're using now.