With a size 12 boot you need a wide board. The rome flag is the wide version of the anthem. It is stiff and good for rideing the slopes and hitting jumps.. Dont think its good for park.. Since you want to go more towards park i would say get the Rome Slash (wide version of the agent) Also, Get somthing smaller like a 158 for park..
if ur gonna be focust on park more then the anthem is a little stiff, go for the rome agent, its allso a great allmoutain board but kills it in the park, really really good park board.. its pretty much a softe custom..