I started making a switch over to LED and found this company had great products and prices.
If you want to retain an old fixture the replacement LED bulbs work fine but we found we liked the warm white bulbs the best for inside the cabin.
I installed four super bright spreader lights last year. Another boat close to mine did his with LED's the year before and the amount of light that actually got to the cockpit wasn't much for the size of his lights. When I put mine on at night, it was like stadium lighting. Mine are so bright I'm thinking of having a separate switch so I only use one. I have two each forward and aft.
Those lights are called Kevin if you want a great outside light.