alright, some specific gear, I know you asked me this over DM, but I figured I'd post here for general reference for anybody else reading:
Speedlights: You already have
Lightstands: You already have
Brackets for speedlight:
Amazon.com: Flash Shoe Holder Type B compatible with Canon Speedlite 270EX 430EX and 580EX II: Camera & Photo
I'm pretty sure that these will attach to your light stands, as I'm pretty sure that the ones you have are a standard mount. If you want to be 100% sure, you can take a picture of it the top of your stands, without the lights attached, and I can confirm for certain if they'll work or not. They will support your speedlight and your umbrella on your stand. You'd need two of them. I know it says 'for canon' but hot shoes are hot shoes. It will work with anything that has a hot shoe, and this will actually be attaching to your radio trigger anyway.
Triggers:
Amazon.com: CowboyStudio NPT-04 4 Channel Wireless Trigger for External Speelights with 1 Trigger and 2 Receivers (NPT-04+extra receiver): Camera & Photo
These will trigger your lights. They're not the best radio triggers in the world, and if you end up doing a lot of portrait sessions, you'd probably want to upgrade to pocketwizards, but I've never had a problem with them, so long as I changed the batteries out when they died. This one set will be all you need for this type of shoot. Don't forget to buy the AAA batteries!
CTO Gel:
Amazon.com: Rosco Cinegel Roscosun CTO, 20 x 24 inches Color Correction Lighting Filter: Camera & Photo
Just buy this and cut out two strips for your flashes. You may not need it, this will only be used if you are letting in a lot of ambient light. If you're shooting against a backdrop that is completely lit with your flash, this won't be needed. All this does is balances the color of your flash with the other colors of ambient light, so that you have even colored lighting throughout. Otherwise you might get blue hockey players and yellow ice. Nobody wants yellow ice.
Umbrella:
Amazon.com: CowboyStudio 33 inch Black and Silver Photo Studio Reflective Umbrella: Camera & Photo
I find that reflective umbrellas are best for sports, since you want a bit harder light than a shoot through umbrella would give, but you still want a larger light source. Two of them.
This kit will get your job done. If you plan on doing these types of things regularly, you'll want to buy higher quality versions of almost everything I listed, but these will do this job just fine. The biggest flaw with the stuff above is durability. Heck, if you take good care of the stuff above, it will basically work as well as much more expensive stuff. Pros pay more for stuff because they often are forced to treat it roughly. If you baby your gear, you can get away with using cheaper.