I don't have pics of mine but you can build one easily enough. Cut 2 pieces of angle iron(2 inch) at a length greater than the panel you will be bending or longer than the longest piece. These will be the vice. Pop holes at the end of both pieces and secure to the bench. Use lag bolts and washers. For shorter pieces pop a few holes closer in. It will keep them from sliding. Take a belt sander to the outside edge of the vice piece to shorten it so the bender will clear it. Coat the surface of the angle iron with painters tape to keep scratches down. Cut a third and fourth piece to match the bench pieces. These will be the bender. Pop holes outside the length of the panel to secure the panel. They will be the pieces that hold the panel above the vice and do the bending. Weld two piece of scrap angle to the back piece of the bender for handles to pull the bender down. When you pull it down the bend will be slightly rounded. Work with a few scrap pieces to get the correct length of panel beyond the top of the vice so you don't wind up too long or too short. It will take a few bends to get the feel for it. Once bent use a large C clamp to hold the bender down as there will be some rebound once bent. Go along the panel with a hammer and beat on the angle iron to get the bend to remain close to 90 degrees. This is mainly for the harder pieces. If you want exactly 90 then take a belt sander to the top edge of the outside vice piece and make the angle a little more than 90 so that the rebound will give you the true 90.
If you want a sharper edge, mark the panel placing the mark right on the vice and not above it, and start the bend as above to about 30 degrees. Remove the bender leaving the panel in the vice. Put the back piece of the bender behind the panel and use the big C clamps to pull it down on the vice to complete the bend. Do this slowly and readjust the back piece as it may slip a bit as you tighten it down. Once down use the hammer as above to complete the bend and get the perfect bend you are looking for. The rounded bends will truely never be noticed, but if you are looking for perfection this is it.
You may be able to do a lot of the bending with the top pieces in place and just use your hands to bend it. Depends on how hard the grade of aluminum you are using is. If you have soft aluminum, you can do the same thing with pieces of scrap wood. Just have to add backer pieces to the wood so it doesn't flex.
If you can't visualize any of this, PM me and I will get some drawings to you. Then again you can rent some time at a sheet metal place or fabrication shop and get it done correctly.
Good advice from Bill and Clive, and make sure you make your brake wide enough for the panel sizes you need. Of course the wider it gets the more flex, and you will need thicker sections across the blades.
Two important things I might add. Make sure you have provision to slide your top blade in or out in respect to the bending blade, this will allow you to make those tight radii, also on Clive's photos notice that the pivot is centered right at the front pivot of the face of the bottom blade, unless this is close or reasonably close you will get a bind.
You should be able to do a reasonably decent unit without much expense.