There is no old growth pine anymore to speak of. That was all harvested out of the SE 100+ years ago. All the pines in FL are at the very most second growth, IOW 100+ yrs old. Therefore, the amount of heart in any given tree is extremely variable. I've had 30+" pine trees >90 yrs old cut off my property with only maybe 6" of heart. You're never going to get the type of wood Tom pictures out of anything we have today. Those trees back then were 4-5' in diameter and had huge hearts.
I have a client who owns an old plantation new me that has pictures of his ancestors hauling logs with an 8 mule team. Looking at the men, I would estimate the log was close to 6' in diameter. That is old growth pine!!
Josh, I've had a fair amount of experience with this. You've got a few things to think about. Having been in your position, I can tell you after a year the borers have done a lot of damage. Look in the bark and at the base of the tree for tell tale signs of sawdust. Under the bark is it will be even more apparent. Around here (NE FL), the sawyers call the beetle bored pine "Levi Pine" because the fungal invasion that turns the wood blue.
You'll need to find someone with a big bandsaw mill, preferably who can come to your house. Having done that, all I can tell you is be prepared to spend a few dollars, and also be disappointed.
I've had numerous pines off my property milled over the years. Aside from the fact I didn't need the lumber, the borer problem is so bad, the last 6 I had taken down I had hauled off. I'm sure there was some good lumber in there, but the borer issue to so had up here its not worth it.
If it were me, I would have the tree downed by a tree surgeon, cut a few cookes off and take a peak inside.
Another issue you may run into is many sawyers will not mill lumber from trees off a homeowner's property due to imbedded metal.
If you do have the tree milled, it would need to be treated to kill the borers, usually by kiln drying.