Very New, Please Help!

For a reef tank, you would definitely want the 2 overflows as it allows you to have better flow and gets the waste to the filtration more efficiently. If it's a fish-only tank it doesn't really matter flow-wise. However, "looks-wise", if this is going to be on a stand as opposed to inwall, you want the back overflows again. Anyone who has a corner overflow tank on a stand can tell you how unnattractive these overflows are when looking at the tank from the side. 2 PVC standpipes, algae, detritus....no thank you.

I have done installations where the person says, "I don't want to know what it is, just make it impressive". So I do. I have had other people who want to know what's in their tank and I actually like that better. Your LFS is likely going to be happy that you want to get involved.