Trust me, if you're in somewhat decent vis water, going deeper than 60ft really isn't any more stressful or difficult than going to 15 feet, all things considered. The only thing you need to do is have your safety stop. I dove the Oriskany with 15 dives under my belt the first time. Was I nervous as hell? Yeah! Was it one of the most enjoyable dives I've ever done? Yeah! Was my nervousness completely unreasonable after I realized just how easy that kind of diving is, especially when all my dives were done in 5' vis? Yeah! It had been several years since I was certified and I hadn't dived at all in that time, due to work and school.
In my opinion, once you go down a little ways you'll see just how comfortable you really are. Take the most comfortable you've ever been in a lake, multiply it by 500,000 and that's what it'll be in vis over 40ft in salt water with good light. You'll almost forget you're at 110ft, I know I did.
Ps- I know it isn't good practice to bring new divers out to the Oriskany or other dives like it, I was just showing that a lot of the nervousness involved in diving deep in the ocean is largely unfounded, so long as you realize that you MUST do your safety stop. I won't mention the name of the shop because that was a good while ago and I can only hope that they've changed their business practices