If you're lifting that much, I'd guess you could do 15 @ 20 / 12 @ 25 / 8 @ 30 (each side). Might be a little lower, not sure how much difficulty you have doing the 25's or how much time in between those sets. +- 2.5 on each side
You can get just about any curl bar probably. Something like: http://www.amazon.com/Champion-Barbell-1-Inch-Chrome-Curl/dp/B0000BYSM2/ref=sr_1_1?ie=UTF8&qid=1430589649&sr=8-1&keywords=ez+curl+bar
The most important part with the curl bar in my opinion is the clamps. I bought these http://www.amazon.com/Power-Systems-8609-Standard-Lock-Jaw/dp/B003G09XDQ/ref=sr_1_3?ie=UTF8&qid=1430589696&sr=8-3&keywords=lockjaw+clamp
They make doing drop sets so much easier, you can switch these out in seconds.
As far as benches, about any of these would probably work: http://www.amazon.com/s/ref=sr_nr_n_1?fst=as%3Aoff&rh=n%3A3408351%2Ck%3Alifting+bench&keywords=lifting+bench&ie=UTF8&qid=1430589798&rnid=2941120011