Didn't know that, Wade- zinc stick-on weights. Well - haven't seen any here yet, but I suspect they are coming.
Dead soft- as in as soft as you can find is what is needed for most rifles. If you cannot obtain dead soft lead, use what you have to, but be prepared to purchase the size mould you need to enable loading them.
The harder the lead, the smaller with have to be the ball, and usually the less accurate they will be- after you cross the 'magic' line - whatever that might be, for your gun and load. Do not be afraid to test for accuracy. Don't be too quick to accept mediocre results. Further testing, might surprise you in a good way.