Endurance and foam thickness

I’m a beginner trying to breakthrough to an intermediate surfer, currently riding a stormblade but want a real board soon.

I noticed that sometimes I burn about 80% of my endurance just trying to get out. I surf a beach break and I understand using the rips, timing the sets, turtle roll, etc.

I was wondering if using the stormblade is contributing to my endurance problem? It’s 9ft.

If I’m looking to buy a longboard, how will the foam thickness, glass level, etc. affect my endurance? Meaning- will a thinner longer board be easiest to get out back or will a thicker shorter board be easier? How will a regular board compare to a stormblade?

Any recommendations on what the ideal dimensions would be for a 6 foot tall guy wanting to ride a single fin longboard with the ultimate goal of nose riding?