I think a close match is a poor man's Kevin Love. Both have nice outside shots, both have post games that are limited yet fairly effective, both are good rebounders.
In his second year in the league, he isn't a poor man's Kevin Love, he basically is Kevin Love. In their rookie seasons neither player shot threes, both players rebounded at fantastic rates. They're about the same size, they were both overweight, and their rates were similar across the board on both sides of the ball. Both were bench players who got occasional starts.
Check out this comparison of their rookie seasons:
http://www.basketball-reference.com/play-index/pcm_finder.cgi?request=1&sum=1&p1=sullija01&y1=2013&p2=loveke01&y2=2009The big caveat, of course, is that Kevin Love took a humungous leap in year 3 and completely transformed his body. A lot of players had rookie seasons better than Kevin Love's.
But yeah, "poor man's" comparisons are lazy. Look at what Love did in college and what he did in his first year in the league, and the Sullinger-Love comparison is actually a really good one.
Sullinger has openly said that Love is his role model, and that he wants to transform himself as an athlete the same way. Let's hope he follows through.