Advice on changing from stock 14 inch rims and spacing

I currently have stock 14 in rims 5 lug 4 1/2 spacing and am looking at changing them.

I found these:
http://m.ebay.com/itm/15x7-15x8-Cra...Tires-for-Plymouth-Duster-70-76-/331635938978
But not sure if I want to spend that much!

Also found these:
http://www.jegs.com/webapp/wcs/stor...Id=10001&quantity_1=1&ddkey=http:OrderItemAdd

But not sure if they will fit?

I don't understand back spacing and offset and what will fit well but not run so any help or thoughts on what I found would be appreciated!

I know the first link ones will fit but the second link are a little different