How big is the chip? looks pretty big compared to most SHA/scrypt chips.

The chip silicon and substrate sizes are in the datasheet [...].  SF3301 substrate is 19x19mm.  Minion is 25x25mm - a fair bit larger, while KnC's public offerings were a massive 55x55mm.
It should be the same size as Spondoolies-Tech's RockerBox [...]. 
( A bunch of this data is in the wiki )