Hi zingzing and welcome to the forums. Youve done the right thing by researching first then asking questions.
The first thing Id recommend is calling to arrange a visit to one of our many fine sponsors. A lot of them sell these grinders and others. That way you can look, play and taste what they can produce.
The Rocky is definitely a good grinder. I have not used a SJ but would guess it would give slightly better results. IMO though you may want to consider other grinders for domestic use if youíre willing to spend that sort of money.
The SJ is really designed as an entry level cafť grinder, thatís not to say it canít be used at home as many CS members do. Personally I would be looking at the Mazzer mini or mini-e which I believe has the same burr set and is probably going to give you the same type of results. Itís a more compact size and therefore more suitable for a kitchen.
You can also look at the Macap M4 or M4D or even a Compak K3.
Again, best thing to do is visit a sponsor if you have one nearby. What is your location?