Thusly "Donegal Paul" Spake
Unto All:

Now we really want to keep a blue lobster , apple snails, a puffer of some
sort and then some other various fishes.

Is this feasable at all??

I suspect puffers don't go with any snails at all. I had T.
nigroviridis, and although they were fairly small puffers, about 10
cm, I could feed them adult Helix snails (aka Burgundy snail, edible
snail, or escargot). They had no problems whatsoever biting chunks out
of the snail, and Helixes are about the size of apple snails.

Actually puffers generally don't get along, period. My nigroviridis
were peaceful, I never saw them chase or nip other fish, but most
puffers will, including, I'm told, nigroviridis.