https://www.lymanproducts.com/brass-smith-ideal-press
Lyman has the most reliable information about their products. You may need to call them or email you specific question. They do have that info available, even if not on the website.
I take it that this is your first press. I have had a Lyman turret for years, and updated it when the the 30 yo one was damaged moving. I do not like those open C type presses. I think you can do all the same things with the Lee breech lock hand press. And not worry about
mounting dimensions. The hand press has been used for pistol calibers and 223. Military 308 will require more leverage.
When you are ready for a bench mounted press, you need a bench, and I would recommend a mount system like Inline Fabrication makes. They also have a swap-out feature, so you can you can use all your presses on the same mount at different times.
The C press will work. So, will the Lee hand press.
My first press was a Lyman turret purchased as the Kit, which provided almost everything needed.
Lyman makes a Universal mount, that allows more clearance, and they also sell plates for it for different presses. I would keep in mind that whatever you attach it to has to be sturdy. I have a Redding O type Boss press That I mounted to a tree trunk log stood on end. It actually works and provides adequate leverage. It will be replaced with the Iline mount on my new bench.