When I replaced the original Bilstein shocks on my 02 FX4 at 100K miles, I stuck with Bilstein. I did not think they were all that expensive. I know they have changed the part number since then so passing on that part number will not help you.
You should also be able get the Bilstein shocks from Ford that are tuned differently from the shocks directly from Bilstein. They are more expensive and not as desirable as the shocks directly from Bilstein in my opinion. I think the Ford Bilstein shocks are tuned slightly too soft for off-road but work well on the street. I now have almost 100K miles on Bilstein replacement shocks and they still work near like new.
I have heard many regrets from people buying Rancho shocks but some are satisfied with them. I rarely hear complaints about Bilstein shocks and use them as replacement shocks for all my vehicles if possible.
FX4 shocks are the same as any Ranger with torsion bar suspension. If it is lifted you might need longer shocks but a 1" torsion bar lift will not require it. I have been running a 1.5" lift on my Ranger since near new and have not had any issues with the shock length or suspension.
2002 FX4 Bright Red Supercab 4.0 SOHC, manual 5-spd & Tcase, 33" BFG MTs, K&N air filter, Modified air box inlet, Gibson SS cat. back exhaust, Bama flash, Hidden Hitch round receiver, Rear helper air springs, Electric trailer brake controller, Line-X bed liner, WAAG bar with KC lights and Wildernest shell.