I use the LED strips available at auto parts stores for cars. They work fine. I wire them directly into the lighting circuits. One issue I have not addressed is their low current draw. The old circuit breakers are much too big - I may go back and add very low tubular low amp fuses to the circuits in front of the lights.
The circuit breaker is to protect the wire not the lights. As long as the wire to the new LED lights is the same size it was then you can keep that breaker. If you stepped down to a smaller gauge wire and the breaker exceeds that wires ampacity then an additional fuse would be necessary to protect the smaller wire..
To do LED's correctly the need current regulation. Good LED's will have this built in, and you'll pay more. In strip or roll form many don't have any current regulation and require and additional circuitry so as not to overdrive them, heat them up and burn them out early.
Good LED's, that will last, use constant current circuitry
Cheaper LED's, that won't last as long, use a buck converter
The cheapest LED's, that can actually catch on fire, use a resistor to try and control current. Don't buy "resistive" controlled LED's..
Be careful what you buy when it comes to LED.