bilstein 5100 or 5125?

Looking to upgrade the shocks on my 2002 Trd, it’s stock height but does have airbags for when I have my camper on. The 5100 and 5125 seem like almost the same shock but looking for some feedback. Thanks

 

5125 is an inverted shock that has ~2" shock body. Inverted meaning the shock shaft goes from being mounted at the top mount to the lower mount. The increased body size allows for more oil and a larger piston thus allowing them to work more before heating up. This is a very down and dirty explanation.