Here's one tip; don't buy buy any more Amiga hardware for now! You have to take some time to think about what you want before you go any further...
Amigas are heavily outdated in the hardware and software department. A 1200 won't make a huge difference compared to a 500. The reason that they are sold new old stock is because someone found a warehouse of 1200s when Escom went bankrupt; not because of market demand!