You can buy a lot of Pex-Al-Pex for the cost of those made up cables, and it will work a lot better, too – plus you’ll have the pleasure of making something yourself.
32mm Pex-Al_Pex would make a superb loop, as it would effectively be a 30mm tube – much bigger than anything you’d normally find (I’ve got 25mm myself), and you can bend it yourself by hand. Expose the Al tube by melting away the plastic with a soldering iron, then drill a hole to take a short 4mm bolt. The exposed Al only needs to be a little bigger than the bolt head, and drill through one side of the tube only. Use short lengths of coax with BNC plugs on one end to connect it to the amplifier (the centre pin will add some strength, even though it won’t be doing anything with the signals), and expose enough braid on the other ends to be able to tin it and wrap it around the shaft of the bolts, in between a couple of washers. Paint the bolted connections with lacquer or nail varnish, and the job’s done. BNC-BNC RG58 or RG59 patch leads are very cheap, so just cut about 5″ off each end to make your loop to amp connectors.
Have fun when you get back home!