before and if possible a mechanical model instead of electrical model.
There are several brands in my mind currently, Apexi, HKS, Pivot, Sard, Omori. Apexi is the only brand I had used before thus do not know how the other brands work. Anyway a new or used is not a problem for me as long as it is reliable and accuracy. Still considering between DIY it or spend some money for installation as I'm quite busy recently due to heavy workload and monitoring my house renovation progress.