Hmm...
of your 4 birds:
White- yes, could be amberlink
Light Brown- I believe this is your ISA
Dark Brown-this is the only one that looks like a cockerel to me, RIR or similar
Black- Swedish black seems more likely
But I'm no expert and we could guess all day long. My local farm store where I get my chicks is super helpful in letting me know about chick shipments, they even let me photograph their order sheet. Can you call or visit and get a list of what was actually ordered/delivered to their store the week you got your chicks? Then you could probably narrow down breeds according to what was actually in stock.
Your run sounds like a nice good size. Even if you end up with 2 cockerels and they do happen to get along fine, I would worry more about your hens getting overbred. The usual ratio is 1:10 and more boys can cause feather loss and stress for the girls which could also result in a halt of egg production, not to mention many roos are not always nice to humans. Here are some articles that may give more perspective:
Keeping A Rooster
Selecting Good Flock Roosters
Rooster Flocks
Dealing With and Taming Aggressive Roosters