Like planes, shaves come in bevel-up (BU) and bevel-down (BD) varieties. Unlike BU planes, BU shaves ride entirely on their toes. The back of the iron has to be tilted a few degrees away from the work, or else it would have no clearance, so there is nothing in contact with the work behind the cutting edge. BD shaves have plane-like soles that extend both in front of and behind the iron.
BD shaves are almost always metal-bodied.
BU shaves come in wood and metal flavors.
Screw and tang adjustment are ways of holding and adjusting the iron in a BU shave. Traditional wooden BU shaves have 2 tangs sticking up from the iron, that are wedged into holes in the wooden stock. They are adjusted by tapping in to varying depths, sometimes with a limit screw so that you can just tap them in until they bottom out. See the adjustment instructions for Dave's Shaves for pictures of tanged irons with and without limit screws. The tangs themselves can also be replaced by screws, which is what WoodJoy does.
For end grain work I think you'd be best served by bevel-up shaves, whether wood or metal. The WoodJoys might be good options, or the LV bevel-up (if that's not the one you have and broke already). LN only seems to sell bevel-down shaves. As noted above the bevel-up shaves are a little tricky because they're only supported by their toes, but it's worth the investment to figure out the various tricks to use them.
IMO you should reach out to LV about the broken shave and tell them what happened. I'd bet they'll get it back in working order for a lot less than replacement cost even if it was your error.
EDIT: FWIW I have all of the LV BD shaves, the LV low-angle, the WoodJoy Master, and the WoodJoy "cigar" shave. For convex or mildly concave end grain work as you describe I'd probably go with the WoodJoy Master or the LV low-angle depending on what toe geometry I want (they each offer two options via reversible toes). As I've said in other threads my 7 y/o son was able to use the LV low-angle and the WoodJoy Master reasonably well with some practice and instruction, so they're not *that* difficult. The cigar shave is a different matter :-).