First stop is the Better Business Bureau: AppolloHosting.com has a satisfactory record versun Infinology unsatisfactory. First flag against infinology.
I have called Infinology once. I don't think I have ever heard so many "hold please" in my life. Was "hold please" about 25 times. After about 14 minutes hung up. Try it yourself. Second flag.
I have heard oh-so-many stories about poor billing issues (often overcharging), as well as tech support not available all the time. Lots of downtime. Third flag.
I've heard of AppolloHosting before, but never heard anything bad.
The best way for you to act is e-mail both, ask questions (try calling) - see how fast and how useful they are in their answers. Ask for a guarantee (or test-drive), etc. All those questions will more likely let them know that you're a serious client and that you expect outstanding service on their part.
Another option is to just list your quote on this forum in "Hosting Requests" forum and I'm sure you'll get even better custom offers (including pricing) than any of the big companies out there for a few reasons: smaller companies are more flexible and they will more likely provide more individual support. Huge companies work primarily with their plans and almost never customize their offers. Anyway, just try this option - see how you do. There are plenty of better hosts here.
Good luck in your search David!