Without a picture of the actual items or a product code it is difficult to tell. If they are of the "Big Hauler" type with their generic bogie type coupler mount I would have thought this would not be a problem. If they are "Spectrum" items with their bogie type and body mount couplers, althought the price would suggest they are not, then it is not a straight fit but achievable. I have seen a rake of Spectrum 2 bay hoppers fitted with LGB hook and loop couplers but it was not a pretty sight.
The Spectrum items wagons come with two different knuckle coupler sets, one to mate to standard 1:20.3 Kadee/AMS coupler height and another set to go to "Big Hauler" height spec, that is also used as standard by some of the earlier Spectrum locos - Shay, Heisler, Climax, etc' - and offered as an option set on the newer Spectrum locos. If not to a spec height and knuckle type only could you not set up a match wagon between them and the rest of a train's conist ?
Max.