I believe this plant has been referred to as Metamorphosis is it the same plant?
Yes the plant is the same, we call it Metamorphosa only as that's what the grower named it, and who are we to argue.
Can it be planted in full sun?
Yes Metampophosa will sit in the sun all day long.
Do I need special compost?
Not special as such but Acer always do better in acid soil or ericaceous compost.
Good for a pot on the patio?