Start by asking and answering these questions: How much past one amp? What battery voltage? How important is efficiency? How much room do you have? Is cost a factor? Do you have a good way to remove heat from the regulator?
Then there's the issue of how the LEDs are connected or driven.
If you're thinking of connecting the LEDs in parallel, you'll find that the one with the lowest initial forward voltage will get more current than the others. As it heats up, its voltage will drop, causing it to get a larger and larger fraction of the total current. So most of whatever current you supply will end up going into one LED. What you need to do is drive each LED individually with its own current regulator, or connect them in series. The choice of regulator(s) depends on which you choose. If you connect the LEDs in series, all LEDs will get the same current, but then you need a regulator which can supply that current at around 14 or 15 volts. If you drive each one individually, you'll need room for multiple regulators. A resistor connected to a relatively high voltage battery is the simplest, least expensive, and smallest current regulator. It's also relatively inefficient and doesn't provide as good regulation as electronic circuits.
