Aaaagh, even 1W LEDs need heatsinks if you want them to have a normal life. And placing LEDs in parallel is far worse if they are not thermally connected (it's not a great idea even then, unless you can be assured that they are fairly closely matched).
And, it's better to use a constant current driver than those variable voltage, variable current regulators. Admittedly, this is not a major concern, but the dedicated devices are smaller and cheaper (although typically not variable)