Delima Grennie Penn 704, 705 or New 706z

[Redsoxticket]

I have a 704 greenie with the silver plate on the side in the family since I was at a young age. a couple of years ago I came across another greenie which I could not pass up. It turned out to be a lefty Penn 705 greenie w/ silver plate instead of what I thought was a Penn 704.

I want to fish the surf and the spinning reels that I have (Shimano Stratic 8000fh, Penn 7500ss, Shimano 6500b) are not reels that you want to dunk in salt water'

The 704 is more forgiving, reliable and easier to clean and maintain but I have a delima.

Do I sell the greenie Penn 704 & Penn 705 for a new Penn 706Z ?

I do not need that many reels to be happy, actually the fewer the better. I hope I will not regret letting go of the greenie 704 but I need to sacriface two reels to obtain the Penn 706z.
or a comprimise would be:

Do I sell the greenie Penn 705 lefty and Penn 7500ss for a new Penn 706z?

Your feedback is always appreciated.

THX