Looking at buying my first Drysuit(used) I’m wondering what rough size i should be looking for. I’m 6’3-4” and 210 lbs

The size charts are all over the place. It depends on what suit you're looking at. You'll have to look at the mfg size charts online.

How much you looking to spend and what are you looking for?

I got a custom fit Seaskin laminate for about $1200.00 bucks. They have a very good measurement guide/system on their website. And delivery was right around the time frame that they said it would be. They're out of England but I see a lot of them here in cave country and enough people are satisfied that they got my money. I have zero regrets and would order another one again in a heartbeat if I needed it.

I’m looking at a crushed neoprene for extra insulation, hows their durability? 99% of my dives are on extremely rocky shorelines.

I'm diving mine in caves and haven't torn a hole in it yet. I know of a few guys who are using their crushed neoprene for true side mount/no mount diving and crawling thru tight restrictions nd they've held up fairly well from what I'm hearing. These things aren't bombproof but for most mere mortals they fit the bill nicely.

That’s good news, i haven’t been diving in a year or so but a dry suit would be a great purchase for diving up at the cabin. 7mm wetsuits are ok up there if you stay above 25 feet, anything below that and you’re wishing you had to piss