What's wrong with measuring up your own outriggers? Nothing wrong with wanting to make your own if you have the right equipment but banging a sheet of steel around a piece of angle iron and hand trimming the flanges etc is quite hard work if you're looking to get a pair of neat and accurate sections. These pieces aren't expensive and IMO are good value for the time and effort saved. You may have to repair the floor above it so you can practice your metal skills there. If you've got access to a box bender and power guillotine, buy one, make 5 more and sell the extras.