I'm looking for a receiver hitch for my rodeo; minor towing only.

I like the round-tube hitches that recess under the vehicle, and have the little "stand-on" rubber step-up pad on top of the receiver. (I'm short) I see these on a lot of vehicles, but they don't seem to be popular online.

sort of like this generic hitch:


I've seen many different hitches, and some of them come with the fine print:
Fits: 1998-2004 ISUZU RODEO EXCEPT 3.5L will fit Sport model.
or "all Isuzu except 3.5L", etc.

I've noticed websites aren't consistent--some say you need it for some hitches, some don't. Yes, I know about different mounting points, but I'm comparing model to model.

When I go direct, for example to Hidden Hitch's web page, they say they don't make *any* that go onto the 3.5L. Anyone know what the difference is in the 3.5L?

Thanks.