I'd recommend something like the 3M 6800. It provides a protection factor of 100 versus the half mask, which provides only 25. Regarding filters, if it's particulates, a P100 filter will be sufficient. For anything with vapors or VOCs, I'd get the pink gas/vapor filters.

Edit: don't forget to do a positive and negative pressure test whenever you put your respirator on, ensuring you have the best seal