Young turtles have more pliable shells than older turtles, it's normal. You sound a little unsure about turtles, which is how everyone is when they first acquire one
Why not get Opus set up and then worry about getting turtle number 2? That way any mistakes you make in set up 1 won't be duplicated in set up 2. I know when I first had my turtle, I ended up changing his habitat quite a bit, and that would be a pain (and pricey) to have to do to two setups... just my opinion.
Also, you should read the main site for tips and care facts for hatchlings... it's a good intro to turtle care
Here's the link:
http://www.redearslider.com/index_basic_care.html
If you'd like, post some pics of Opus and his set up and people will give you some guidance if you're unsure about things, it was really helpful to me to see pics of other people's set ups as well, so that I could see what worked for other turtles.
Good luck!