Personally I never slice mine, I think they are much better pulled especially considering the higher amount of fat in them.
As for searching for a good one you want one with some good marbling and not a HUGE main line of fat running through the middle of it, some of them can contain as much fat as meat.
Also look for one that isn't falling apart on itself while still in the package, sometime the meat will begin to separate from the fat and that just causes that much more of a PITA when smoking.
It is similar to a sliced brisket but also different, many folks will argue whether brisket or chuckie is tastier so it's a personal choice but they are both soooooo tasty.
And no need to apologize for not knowing what's doing or for all the questions.
How many of us out there didn't know this or that before getting help from other fellow smokers.
Long as we can help you have a successful and tasty smoke then all is good
*on the edit
I would go to 190-195 for slicing and 205 for pulling.