The most light for the money is H4 upgrade.
It's simple. Just replace your current sealed beams with a H4 housing and bulb.
You can buy the H4s in DOT spec or Euro spec lenses. The Euro spec lenses are not "legal" in this country. I can't imagine anyone ever getting a ticket for the Euro lenses. If I knew about the difference when I bought mine, I would have bought the Euro lenses.
There are two things you can do to provide better lighting and one involves a little bit of labor and the other costs around $25.00.
1)- Clean you headlight grounds on the back of your grill panel. I cleaned mine and the voltage at the headlight plug went from 10V. to 11V. as measured with a Snap-On digital multi-meter. About a 10% increase.
Just remove the screws and scrape where the ring terminals attach to the grill panel and scrub the ring terminals with a wire brush. Assemble with a dab of dielectric grease.
2)- Buy a headlamp relay kit online. This provides voltage directly from the battery, rather than routing the voltage through the already weak headlamp switch. Potentially providing 14V. to the headlights.
Do these two upgrades prior to the H4 upgrade. You will still want to do the H4, but you will get the best performance by cleaning the grounds and having the relays in place. Plus you won't have to worry about your headlight switch.
For more info, search this forum for "H4".
Good Luck, L.M.
1987 YJ-4.2L-Standard Shift- Re-manufactured Carter Carb-2" body Lift-31X10.5X15 BFG KOs-188K Miles
HEI distributor with computer and all related relays and wiring removed.
No back seat.
12K Badlands winch with dual batteries.