Very different boats... Either would make a decent coastal cruiser, neither would be considered 'blue water' boats..
The Santana is more of an IOR influenced masthead rig design with a high aspect main and larger jibs, genoas and spinnakers. The J is a fractional rig boat with more power in the main and smaller headsails. The Santana might be 'cruisier' from a living aboard perspective but the J will likely be a bit more fun to sail and will be better behaved overall. The smaller headsails will make the boat more manageable esp for a couple.
Both are decent boats... try to get on board each and see which one 'speaks' to you. Either will need close inspections/survey with a view to identifying any issues with delamination and wet core in the decks, and I believe the J has a (at least partially) cored hull too. Not a bad thing unless things have gone badly from undetected leaks here and there.
Good luck... Lake sailing, I presume?.. I'd probably lean toward the J if it's a good one.. but I'm partial to fractional rigs...
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)