One good hting about jumps is that you don't necessarily need standards...
Any of these can also be used as "standards" with poles on top of or resting on for cavaletti/cross rail style jumps:
Empty 55 gallon drums (two feet 6 inches lying down, 3 feet standing up)..standing up can also be used with two poles to create about a 16 inch crossrail or lying over top the barrel, a full 3 foot jump.
We use wooden fence posts and concrete blocks. The blocks are great because they have 2 different holes in them to increase jump size, and you can put one on top of the other. If the horse hits into the wood they fall down easily so he won't hurt his feet, too.