Mattress Forum

I've read a ton on this forum and I love what I've read.

Background:

Currently own a 5yr old beautyrest that had a 1.5+ inch sag.  I did surgery and took off the mattress pads (both sides) which had a 1-2 inch cheap foam between the springs and the pads.  I did a level over the springs and they look to be in sound condition as they were all perfectly level in all angles.  I love a softer feeling bed and would be willing to try out a couple before I end up buying.

I am a 170lb, 5'11" male with a tone body type.  I am a 40 percent side sleeper, 60 percent stomach sleeper.  My problem areas are lower back with some shoulder pains.  I play quite a bit of volleyball so I'm prone to lower back pains as that is what gets sore from the sport.  I live in Minnesota so would look to either get shipping here or a localish vendor.

Plan:

My plan was to go with the springs as the support layer with my comfort layer consisting of a combination of a 3" 24-28 with a 1-2" layer of 15-20.   I have read that natural tends to need a higher number then a similarly rated blended so I was leaning more towards 28.  I figured a 2" layer of 19ish would be perfect for the top layer.

I may, in the future, end up going full talalay and later convert my support layer to a 4-6" 30+ core but I wanted to go with strictly toppers to start off with and utilize my existing support layer with the springs.

Is this a sound plan?

Am I off in my comfort layer of 3" of 24-28 and 2" of 19ish? 

Is 24 or 28 a better number to aim for in natural?

With this be reusable later on when I go full latex if I decide to go that route?  

Thanks for any and all advise as I'm looking for a couple of the heavyweights on this forum.

Thanks in advance, 

Matt