Which MagLED drop-in for a single Li-Ion battery?

I was thinking of running a single protected Li-Ion battery with a MagLED drop-in for something I'm putting together but I was reading the specs on the AW cells and the protection circuit kicks in at 3 volts, at the rated voltage of 2 D cells. Should I get the 2C/D version (I believe that this has a boost circuit) or the 3C/D (buck?) version for this battery? The concern is the 4.2 volts of a freshly charged Li-Ion cell. Would this be too much for the 2C/D version?

Before you tell me to look into a different circuit or setup I'll just say that the host is mostly ready for the drop-in, I just need to know which one to get.

Probably the 3 cell.

Thanks for the reply.

I'll post pictures as soon as it is done but it could take a while.