For a power hatch, looks like any version -4BA1A, -4BA3A or -4BA4A (the latest) will work. However, those aren't gas struts, they're spindle motors. If they lift the gate to the top and then drop down, then it doesn't sound like you have bad ones. Chances are you have a mis-calibrated ABD Controller or a bad sensor. Get the DTC's (codes) in your ABD read by the dealer, or someone with a high-end scanner like a SnapOn Solus that's capable of talking to it. Btw, if you simply replace the spindles, the hatch won't work at all until it's reset and calibrated. Same deal, requires a scanner.