You're in for a steep learning curve. The standard advice here is to get a settop FTA receiver first, set the dish up, concentrate on learning how to aim at one satellite. When you have that mastered then you can move on to the motor. Motors have their own learning curve too. THEN you can slave your USB box to the FTA receiver and get what you want. That's how it was suggested to me, that's how I did it, and having done it, That's how I suggest everyone do it. Yes it seems like a pain from the outset, but there are very good reasons to do it that way, that will only become apparent when you actually do it. But once you do it, you will quickly understand why.
Setting up a motorized dish with JUST a USB Box is gonna be danged near impossible. They're just not designed for that.
As far as suggestions....I use old Primestar dishes...hey, they were free. But if I had to buy a dish I'd get a 90 cm/1m dish providing I had a place to ground mount it. You want, if at all possible to mount your dish on a pole concreted in the ground because you WILL be spending a lot of time out at the dish aiming, tweaking, etc.
Now, as far as specific receiver reccomendations...you can look in my sig and see what I have, out of all of them I like the Coolsat 5000 the best. It was my first receiver, but I still like it the best. They do not sell them anymore to my knowledge, but you can get a 6000 which is about the same, function-wise.
Motors, all I have experience with is the Sg2100, I like them, I have two, they are solid pieces of kit.
Hope some of the above rambling helped.