speckled sussex will give you a cute but yummy decent size birdYou may want to read the previous posts regarding SFH, esp if you are planning to use as a dual purpose bird or process extra cockerels, they are not a good investment imo. The peeps on the SFH are quite in love with them and refuse to admit that the meat yield is as pitiful as it is. A friend of mine who raises them has gotten max 3.5lbs dressed. Almost not worth the effort...there are many other breeds that are much better for dual purpose.
Good luck with your cooler bator, would love to see pics!