Stroker:
Pros: All your engine accessories and underhood components still fit. You can maintain a completely factory appearance if that's your thing.
If you already have a 302 block, you can use it. 289s are reported to have shorter cylinder skirts, which limits the amount of strole that can be added.
All the components for 331 to 347 cid strokers are pretty much off-the- shelf parts these days, and not greatly more expensive than stock rebuild parts.
Cons: There are rod angularity issues with 302 based strokers. Over about 331 cid, piston ring placement becomes a problem. Accordingly, large 302 based strokers tend towards high oil consumption and premature cylinder wear.
Some of the Chinese-made stroker parts have been known to have quality-control issues in the past.
351W:
Pros: Basically stock rebuild should cost less than 302 stroker. More cu. inches. 351W has beefier block, bigger rod and main bearings and uses larger, stronger fasteners for critical components like head bolts, and rod and main bearing caps. No rod angle or piston ring placement issues. Should be more durable, long term.
Cons: Have to buy a rebuildable block. Engine is physically bigger which makes spark plug access more difficult and can cause hood clearance issues with a high-rise intake and stock air cleaner assembly. New accessory brackets and pulleys may be needed. Engine is heavier.
As you can see, there are trade-offs either way you go. Personally, I like a 351 because of its inherent durability, reasonable rebuild costs, and aluminum heads and intake will bring thje weight down to or below factory 289/302 territory.
'92 block is fine, it'll be set up for a 1 piece rear main seal, which is a plus, and 351Ws never went through the lightening/re-balancing process the 302 got in '81, so later blocks are just as strong as the early ones.
'94 and newer are considered the "premium" 351W blocks, because they come machined for a roller cam. Depending on what you have planned, that may or may not be am issue. There are roller cam retrofit kits available, if that's a priority to you.
289/302 headers may or may not work. The 351W deck is taller which will pull the headers closer to the floorplan. Depending on the design, there could be enough clearance to work. But unless you can find someone with your exact combination already, it'll take some careful measuring and/or trial fitting of the specific headers in question to know for sure.