Tarpon 140 Scupper Plug size?

I picked up a new Tarpon 140 and I am really enjoying this boat compared to my Malibu II barge.

I was looking to order some scupper plugs for the 140 but I am not sure what to order.  It looks like the Ocean Kayak size small would probably work.
http://www.rei.com/product/710389#

Any recommendations?  I am currently using foam golf balls, but I need some more secure.

Brian 3d

Small fits very well and does a great job keeping the water out (except for paddle drips of course).

Small fits very well and does a great job keeping the water out (except for paddle drips of course).

Thanks RF.
I know there will always be a little water down by my feet, but at least it will not be a live well.

Gork say "Livewell good! Big lingcod love eat fresh Greenling!"

Gork say "Livewell good! Big lingcod love eat fresh Greenling!"

Oh man, I am just waiting to land a big ling on my tarpon.  It may not turn as quickly as a Malibu2 but it is so much faster who cares. 

I think I will need to upgrade my waders for a wetsuit and then venture into the salt after Mr. ling.

Foam golf balls fit all scuppers.  That said scupper plugs in the ocean aren't my cup of tea.

That said scupper plugs in the ocean aren't my cup of tea

Ditto. I only plug when fishing the Lakes.