If you want adjustable pedestals, or any pedestal for that matter there's Springfield and Swivel ez, , I think those are the only two. From a stability stand point I can only speak for the "taper-lock" style. They have a little lever that locks them into the pedestal mount. They are super stable and don't rock or wobble. The down side is the pedestal mounts may stick up a little higher than you might like. Plan on spending $100-$130 per pedestal. You'll need the shorter pedestals, , I think they go from like 14 inches and rise to 18 or something like that.
Keep in mind that wherever you put a pedestal mount you will need to have an aluminum sheet .060" to as thick as .100" and about 1 foot square under the floor board. This will do two things, 1) give the pedestal mount screws some metal to bight into, and 2) make the area where the pedestal mount is a little more rigid.
From experience, Lund does that for every pedestal mount.
As far as seats go, your pretty much relegated to aftermarket, like what you find in the iboats store.
Some years ago I rebuilt a 17 foot Lund American that had twin consoles, bought it as a project boat. Most of the floor was so rotten I vacuumed it up in a shop vac. But, under each pedestal mount was a sheet of aluminum. My 97 Lund Tyee has the same thing.
Anyway, when it came to seats I had to spend a few bucks to get something that looked nice and was comfortable. I ended up buying my seats at not iBoats.
What's cool about rebuilding a boat is once you have the tub stripped out, it's almost like you have clean slate to some degree. I retained the consoles and live well and such, but there were a couple other compartments that I redesigned to be more usable.
For what it's worth, I rebuilt mine for the long run. Most or all of the wood I used was Medium density overlay. EXPENSIVE but it would last a long time. The floorboards I wanted sealed. The bottom side that no one would see, I went to the hardware store and bought any color paint, something that someone returned cuz the color sucked, didn't matter, it was going to seal the wood. The top side was carpeted with water proof marine carpeting.
While your rebuilding, plan out for interior lighting, and a place for 2 or 3 power ports (the cigarette lighter kind) so you can plug in a spot light, bait bucket, electric cooler, charge a cell phone, etc.
It's a lot of work but it's fun! Good luck!