By the guide, your next purchases should be She-Hulk and Invisible Woman, followed by Human Torch, Quicksilver, and Storm. I stand by that. That said, the best advice right now is to save your Command Points. The Age of Ultron tie-in is likely to start in the next couple of days and we are all anticipating content such as a movie Quicksilver or Hulkbuster Iron Man, and you will want your CPs then... and you will probably want to have A LOT of CPs then.
Generally speaking, do not buy any characters who cost more than 90 CP until you have all the characters who cost 90 or less; just because they cost more does not mean they are better characters (they're not).
Level all your characters to 7 as quickly as you can. Seven is the most efficient level for PvP bonus.
The only alts you need to consider in the near future - aside from maybe movie promotional suits - are tactician Grey Suit Black Widow and Blue Suit Quicksilver (either class). Don't worry about buying any other suits; they are not an efficient use of your CPs at this point.