I read on website that these were one the worst silver investments as they've priced quite a lot above the actual value of the silver

Britannias, American Silver Eagles, Canadian Maple Leafs, etc all have high premiums to buy but typically you’ll get a better price when selling them that you would for generic silver.

What to buy is the eternal stacker’s dilemma. Not all of one thing might be best. I have mostly ASE’s, but also some bars, generic rounds, and 90% pre-1965 coins. Only a tiny bit of gold, I personally prefer silver.