I had a similar experience with crappy jacks - plane was nearly to the top when one of the jacks started to lose pressure. I figured the investment in good jacks was a lot cheaper than poking a hole in the wing.

 

I have the Meyer A9 227 model. Photos attached. In order to work, I had to remove the wheels on the jack. Also a little trick - when pushing the plane back, it is about 1/4 inch shorter than when pulling forward. To get it to go on the jacks, I have to push the plane back past where I want it to be, then pull it forward about a foot. I modified the Lancair jack cups - essentially had a machinist turn the screw in jack cup into a point that recesses into the top of the jack. The jacks have a steel pin that recesses in the side of the jack ram - thus, the hydraulics are only used to raise and lower the jack, but not to hold it. I find the jacks to be very stable during gear retraction testing.

 

Also attached photo of my idea for rear stand. Welded from steel. I used a standard 1/2 inch socket universal for the rotation point, with a bolt welded on the top which screws into the airplane tie down. I use lead shot (available from the local shot gun reloading outlet) for weight.