I have cats too, that's why I can't have open top tanks (and I really like that look too, darn it! lol)
As a last resort, I have a local glass shop that I use for glass for art projects (kiln work). He's very resasonable and could cut me a pair of glass panels to make a "short" versa top - I'd just have to cut down the plastic hinge. You can also buy replacement hinges online and cut one to size.
I also read a thread on a cichlid site where a guy & his buddy make their own versa-type lids (those cichlid folks are sure crafty). They would cut two pieces of glasss to the size needed, lay them down in position, butted up tight against each other (laying them back down as if they hadn't been cut yet, as they would look on the tank). Then they tape off a seam - like you would if resealing a tank - so the tape was postioned a 1/4" away from the cut line. Then they ran a bead of 100% silicone caulk the length of the cut line, smoothing it with the index & middle finger. By drawing the two fingers along the bead, it creates a peak in the silicone - a pyramid shaped bead. Remove the tape, let dry. They said it's important to get the silicone on top of the glass seam, not in the seam - inbetween the glass - because then the glass wouldn't be able to move if it's in the seam.
According to them that makes a perfectly flexible silicone hinge thats clear, not black. (The whole point of making tops & hinges like this is to aviod the black seam in a versa top, which interferes with the lights if they rest on the glass like mine do)
They say if the hinge needs to be redone in time, it's a breeze to do. I always thought this mini project sounded easy to do.
A glass cutter should be able to cut the glass to size & grind (sand) all the edges for very little $$. If you cut your own - which is easy to do - just remember to sand the edges. And don't get cut!
As for a special shape around the actual HOB itself, I would use thick acrylic, or better yet you can buy replacement parts for versa tops. You can get a hinge strip, but you can also get the clear plastic "flange" (don't remember what it's called) that fits on the back piece of the glass. That part that sits on the rim and where you make cuts to accomodate heaters, filters, etc. After buying a replacement "flange" you can cut it to match the short length of each of the end pieces of glass, and trim them to fit around the HOB. If you had this clear flap on the rear of the tank where it belongs, as well as on the end of the two pieces of glass where the HOB is, you would not need an addition brace at all - you wouldn't even be able to use an additional brace. The glass top would be sitting in the rim on it's glass edges on the front & center sides, and on the clear plastic flanges on the back and HOB sides.
I'm posting this before I go to work early in the AM, I hope I'm making sense! lol (no coffee yet)
