Welcome to CoffeeSnobs [smiley=thumbsup.gif]....
Well mate, Id do away with the "handstand" tamp for a start, no need to tamp that hard.... 12-15Kg is plenty. The secret to getting the ideal pour is mainly centred around grind size, dose and distribution; and if you can manage your tamping force to be consistent within the range above, all will be well.
Dose and distribution is the hardest of all of them to learn and apply consistently so thats the best place to start. Basically, I wouldnt bother trying to use the Single Basket its much harder to Dial-In so would just stick with the Double for now. Try and find the ideal height to dose the basket by dosing, tamping and lightly locking in the PF into a "Dry" Group. Keep going until you arrive at a dose that realises a light impression of the Shower-Screen/Nut/Screw-head on top of the puck and then just back off a little from that.
Next, start pulling shots for real while keeping everything the same and only adjust the Grind Setting until such time as you achieve consistent pours of the right volume within the 25-30 second time bracket. Dont get too hung up on the exact time as the most important thing to watch out for is "Blonding" of the shot as this is when the very bitter elements of the brew start to extract. The idea is then, to stop the shot either just before Blonding is about to start or at the very first signs of it. The whole process then comes down to practice, practice and more practice until such time as all the elements of pouring great espresso becomes second nature to you.
All the best and Happy Brewing :),