What is the difference between a Bronco bass guitar and a J bass guitar?

So I was interested in getting into playing bass guitar and i wanted to know what's the difference between a Squier Affinity Series Bronco Bass Guitar and a Squier Affinity Series J Bass Guitar. When i mean the difference, I am looking for like the weight, length of the neck (if one is longer than the other) and just anything else. and also, since the J Bass is a little bit more expensive, what does the J bass have that the Bronco bass does not? and I play punk rock (on guitar and would like to play it on bass as well). and no i don't mean the false punk bands like blink 182 or green day. i mean real punk rock bands like Bad Religion, NoFX, Anti-Flag (<- yes i know all anti-flag songs are impossible on bass, im not trying to learn those songs), The Flatliners, Rise Against, Pennywise, Strike Anywhere, Descendents, Against Me, The Clash etc.......................-----------And attached are the links to the 2 guitars. a href="http://www.guitarcenter.com/Squier-Affinity-Series-Bronco-Bass-Guitar-100453641-i1146354.gc" rel="nofollow"http://www.guitarcenter.com/Squier-Affin…/a a href="http://www.guitarcenter.com/Squier-Affinity-Series-J-Bass-102581444-i1150678.gc" rel="nofollow"http://www.guitarcenter.com/Squier-Affin…/a and please dont tell me to go to a physical store and ask an employee because im too busy with studying. Thank You!