I'm about to receive a set of fancy* aftermarket skids:

1996-2002 4Runner Drivetrain Skid Kit

I'd give you my stock set if you were nearby. It really depends on how much danger you are expecting to expose your underbelly to. I plan to slide and grind so I got a set of sliders first and now some burlier skids. If you will stick to trails without sharp rocks or boulders, I wouldn't bother with either - just get a used OEM 2nd part skid to go with your OEM front.

*not as fancy as the Savage stuff i was just about to order before he closed up shop. I just got an email response to their online form I had filled out in early Jan and hoped for a miracle, but it was not to be. RIP Savage.

4XI also takes PayPal so you can do the Pay in 4 interest-free scheme in case you are a paycheck-to-paycheck 4-Wheeler like me. LOL.