I'm getting all confused

I hate to change to different tires NOW, that I already put 2 new TA's on the front, but getting the rears will be a problem! I am tempted to do the Avon's, knowing I have some awsome tires would be very nice, but they are alot of $! The billboard's lettering looks to big for my taste. I checked on the Cooper tires and they are real cheap online. About $356 for the 4....but.....they want $121 for shipping, which is a joke!!! There is a local dealer here in Vegas I can probably go through if I want, but if they are not a whole lot better than the TA's, what's the point. Can I put 245's in the front? I have 235's now. I will have to give it alot of thought!