I dunno about commemorative maps, but there's a lot of Carto on the web already, of South Sudan. I guess it having been the location of so much strife and misery over decades, a lot of attention has been focused there. The UN Sudan Information Gateway has scads of maps, from vector infographics to scans of excellent paper maps. I saw for instance excellent 1:500,000 Swiss-produced topos, and in their title blocks are mentioned Russian Military 1:100,000 and 1:200,000 series. Lots mention sources like Quicksat, Landsat, Earthsat. There's a growth map of the capital, Juba, showing spread between just 2002 & 2007, including building types. Cool stuff.

Even with those resources, Google has been helping sponsor map improvement events, to get the new nation some better data to work with.

Univ. of Texas' Perry-Castañeda Map collection has links to 1:1,000,000 and 1:2,000,000 topo maps of the area - albeit as 30 to 50-year-old data. The topography hasn't changed much, though. The South Sudan government has a bunch of data online - stuff like land use planning at 1:100k and 1:50k.

Of all the online South Sudan info, I admit to being trivially tickled that their president knows the value of a good hat.

Incidentally, Sinnyo wasn't claiming that map - it's from Wikimedia Commons.