Hosting – I suggest joining the WordPress Hosting and WordPress Speed Up Facebook Group and see what real (unbiased) people are saying about hosting. SiteGround was #1 in multiple Facebook polls and #1 in most Facebook conversations (this one too). People who migrate usually see significant load time improvements especially if they’re currently using Godaddy/EIG. I use their semi-dedicated GoGeek plan which comes with 4x more server resources than regular shared hosting (#1 factor in WordPress Optimization Guide) and have <1s load times with 100% scores in GTmetrix/Pingdom. SiteGround also does free migrations.
Be sure to check what kind of customer support you can expect from your affiliate program once you have signed up. Do your research online and if possible, speak to other sellers using the program to get their thoughts. Can you speak to someone via phone or Skype or do you have to wait 72 hours for email responses? Be clear on this because trust me, you will need support at one point or another.