I used LEDs from
Rigid Industries. These guys specialize in LEDs, and they make LED light bars for fire/rescue/offroad, marine lighting and other cool LED fixtures.
These fixture inserts (not really a "bulb") are about $20 each but are plug n play in the fixture, have a nice warm color temp, are very bright, and consume very little power. One died last year and a quick email to the company got me a new on in the mail.
Yes you can get much better prices on flea bay, but as wa8yxm says, you pays your money and you takes your chances.