Honestly you dont have to get 2 Dorans Rings but i think its actually a viable option. It gives you a little bit more HP mp5 and AP for 475 and when you need the extra space it sells back for more than half. Having said that when it comes to getting 2 Rod of Ages thats a definite yes. The hp and mana you get from having 2 is amazing not to mention that it makes archangels give you all the more AP. Rabadons is a no brainer, 155 AP +30% bonus AP, yea ok enough said. Getting 2 archangels is also a bit awkward but is worth it in the end. The amount of mana you use spamming your spells definetly builds up and having 2 Archangels gives you an immense amount of mana and mp5.