If you are going to keep your Viper stock or mod it like you have done or even mod it further, then you will be very happy with the VEC1. My VEC1 increased my Viper's drivability in ways that it was very easy to notice. The VEC1 will also work on other cars & trucks, too - I'm going to put mine on my heavily modded Dodge Ram Pick Up now that I have the VEC2 in my Viper.
The VEC2 is for the Roe Supercharged Vipers and it does things that aren't needed for non supercharged Vipers.
Both install in 45 minutes (VEC1) or less (VEC2). The VEC1 cost about $410 plus shipping and the VEC2 cost a little more because I was the 35th person to get the Roe Supercharger and Sean sold it to the original run of superchagers at cost, so it may be a little higher to you.
Call Sean and he'll explain it all to you better than I can, but my bottom line is they both work great and are well worth the money.