I think lead times vary on ordered products, but I ordered an indigo LED through their ETSY store and it took a solid 3 weeks.
As far as swapping out the quick connect LED's, results vary on that as well. In theory it should be easy, and is in practice, but stuffing those tiny wires back down inside can be problematic, considering there's no way to organize them so they just kind of bend every which way and get pinched. I personally think there must be a better system for this, but I'm not an engineer.
The bottom line is that you'll probably be just fine swapping out your LED. It was why the quick connect was designed in the first place. It's as easy as pulling out the LED module, disconnecting the quick connect, connecting the new LED, stuffing it back in, then tighten the retaining screw. DONE