The marker lights are just standard 194 bulbs. They're all over Amazon, ebay, autozone, etc. You'll need an electronic flasher module to run them or they'll blink fast. I love LEDs, but found them to be dimmer than the incandescents in the marker lights due to the reflector design.
I have LEDs on my F250 and 2 door Tahoe, but they're also $300 sets and not cheap $50 Amazon specials. I wouldn't run cheap LEDs as my main headlight.92-96 use 9007 IIRC. Most LEDs are inferior to halogen, do your research. 4000-4500K is ideal, 5000K and above are bluish and much less effective. I went through 4 sets of LEDs on my camaro before finding ones I liked. I decided to purchase a pair of Hella 500FF for the bronco instead and do not regret my education decision. I'll be doing new headlight housings at some point, but probably keeping halogen bulbs.