I know I'm not part of the commonwealth, but we ship quite a bit of performance parts over the border and quite a bit more to the mailboxes on the US side of the border.
I have seen plenty of people claim you can use the AHU springs in place of performance springs. If you saw the length of the inner AHU springs compared to the ALH or the dual springs we use, you might understand why I disagree. And the spring alone is not the way to install them, as there is a washer under the springs to hold the center spring on center and to the correct height.
I need to show the springs lined up one against the other to show what the problem is, if using the AHU springs. To give you an idea, the AHU inner spring is comparatively short and will have very little contact pressure. The real purpose for the dual spring setup is to suppress harmonics from high boost, so 'rag-tagging' an incorrect spring is not going to get you where you want to go.
That said, if anybody wants sets of AHU springs, I have a big can full of them. Let's make a deal... what are they currently going for?
Seriously, if I read your build correctly, it's a VNT-17 you are expecting to build with? If that is the case, I don't believe dual springs would be necessary, as your choice of turbo would limit your ability for maximum boost, below what the dual springs will find any function. Understand, the additional valve spring pressure is not to suppress 'valve float' in the conventional sense, as there is no way the engine can reach those engine speeds, at least, not any way I'm interested in making this engine perform. It's boost pressure that will cause the issue with valves settling down and it's referred to as 'harmonic suppression'.
As a price comparison, our Stage II cam goes for $400CAN. Our pistons and rods are also competitively priced, as is most everything we do. When piston and H-beam rod combinations are purchased together, we balance the pistons and rods in reciprocating sets for free.
If really big performance is required, we have the Crafter pistons, with a CR drop of 16.8:1. If the goal is 300hp, that is a real consideration.
We have great access to the Jeep adapter plates, if that is where you are going.
Questions? Feel free to call.