I think that your shocks are made by Bilsteins, which means that they are monotubes. Any monotubes are better than OME twin-tube shocks...and from what i have heard of OME shocks, they are not particularly good. I think that the aftermarket Bilsteins are beefier than what came on your truck, despite coming from the same company.
Personally, i would just get +1 tire size. I would NOT change your shocks. Those stock Bilsteins should have no problems controlling your suspension...and very unlikely to fatigue with any off-roading that most of us (99%) do. Monotubes are excellent at getting rid of heat buildup...are fast to respond...and lasts a long time (as compared to twin-tube shocks). The only negative to monotubes is that they can be damaged easier if hit by a rock (single tube chamber) and, in aftermarket application, tends to ride stiffer. Because of the latter, i would stick with the stock Bilsteins because those were tuned specifically to the 4runner by Toyota & Bilstein engineers to provide the best ride compromise. (You can search for my name...i had aftermarket Bilsteins on my old 2002 4runner...i ditched them after 6 months in favor of stock shocks due to the rough highway ride.) YMMV.