Looking for GAZ GHA Coilover

For several months i have looked for suspension upgrade. Read a lot of review, read hundreds of post on many MX5 forum... My budget is very limited, so i must find the best quality/price ratio kit. I want to eliminate the understeer of my MX5, now is too bouncy on turning, and is seriously tall... It looks like a 4x4!
Some month ago, i was looking for Koni shocks (fixed height and top adjustable for damping rate), H&R or Eibach springs and FatCat Motorsport Bump Stop , but at the end the price is similar to a complete Coilover Kit...
Now, the question is: Tein SuperStreet or Gaz GHA Coilover?
Tein SuperStreet has a lot of good review, Spring rate 4Kg/mm Front - 3Kg/mm Rear, 1300€ on Italian Shop or about 1000€ on Ebay UK.

 

Gaz GHA for MX5 NC is newly on the market and there are not more reviews...

Spring rate are 6,2Kg/mm Front - 4,8Kg/mm Rear and the price is very good! about 500£ in UK with shipping.
One MX5Italia's user has buy this kit 2 weeks ago and he give a good feedback. He said "nice quality/price ratio"... So i'm looking for this kit too...

Here some photo of his MX5 NC with Gaz Height Adjustable Coilover:

 

On the Box:

 

 

Mounted:

 

Really Low: