You don't want to go this route. My friend has Hella housings with
H4 LED Bulbs in them. While the light output is better than stock, it's nowhere near as good as my Truck Lites.
This is the same principal as putting HIDs in a halogen housing, it's a huge no-no. Different types of bulbs were meant for different types of housings. When you throw an LED bulb (or HID bulb) in a housing with reflectors meant for halogens, it will be bright, but the light output is scattered, technically illegal, and will often times blind other drivers.
Please, do not do this. If you're on a budget, just save up. You can get a nice set of LED lights for $120, of if you're stuck on halogen lights, you can get the
Cibie 7" H4 Headlights,
Hella 7" Vision Plus H4 Headlights or
KC HiLiTES 7" H4 Headlights.
I'm not just making this stuff up either. Talk to anyone who is a lighting engineer and they'll verify this.