I don't know know where to find your exact seat. It might be out of production. Email Grady White and they can point you in the right direction.
Any seat with your preferred dimensions can work. If the seats in your 2005 Journey are anything like our 2005 Islander, there are plenty of better options if budget is not an issue. One of my priorities would be to find a seat with fold up arm rests. It would make squeezing through the helm easier.
The ladder backs from Wise are similar to what our boats came with.
If money were no object, I'd go for the Pompanette.