big end connecting rod bearing

None that I have seen yet. Apparently it is an oddball size. If the bearing race in the rod and on the crank pin somehow miraculously survived you may get lucky and find replacement rollers at a bearing supply store. They will need the diameter, length and number of rollers as well as the intended application.
Most folks would just buy a replacement engine and keep the dead one for spare parts.
If you want you could also buy a replacement crankshaft and new end bearings.
After pricing that, the bearings, the gasket kit, and the labor time involved to do the swap it usually comes very close to the cost of a new replacement engine.