you can get soulstones a few ways:
1) use a veteran reward (for playing at least 1 year) and choosing the red soulstone, which is bound to your account (only your characters on that account can use it), it is of no use to anyone else except maybe as a house decoration.
2) you could buy a legacy token from EAMythic this give you the choice of several older items from past releases, one is a soulstone (a green one if I remeber correctly.
3) Somewhere on your shard there might be a few player vendors with a soulstone token on them. It will be very expensive (gold wise) but if you can find one, it will turn into a soulstone when you use it.
As far as soulstone fragments go:
1) look for soulstone fragment tokens on player vendors. price will vary from shard to shard, but it should be around 185, 000 to maybe 500, 000 gold.
2) you might be able to find soulstone fragment tokens at collapsed houses of former players, I found a few this way.
3) continue playing UO, and EAMythic will give them out again to all players. EAMythic has given soulstone fragments out a few times, I am fairly sure if you play long enough, fragments will be handed out once again.
