Hi Dodster
If they are side steps, as opposed to side bars then they'll only be designed to take the weight of a person, and may bend up and contact your bodywork when you put the weight of your TJ on them.
If they are bars then take a look at the way they are mounted. If the bars and mountings look like they'll take the full weight of the vehicle then you may be OK. Worth getting a second opinion before you go spending your hard earned cash, and one advantage of stainless is that you won't have to keep painting 'em!
If you end up buying a new set then there is a lot of choice out there. I have Olympic rectangular nerf bars on my TJ, which are heavy-duty, and which I've been pleased with. Tomken make some really sturdy bars too, but they weigh quite a bit more than the Olympics.
Bear in mind that whatever you put on will add to the weight that your springs are carrying, so if your suspension is a bit saggy then heavy side bars will emphasis that. You might consider something like rocker guards, that wrap around the sills instead, as they may be a bit lighter.
It's worth contacting Mountain Jacks to see if they're making anything themselves (which will save on the shipping charges). Come to think of it you might as well give them a ring anyway, as I found their prices for my Warn bumpers to be the cheapest around, and their service is excellent too.
