Your front travel is limited by your bumpstops. Changing your front shock length alone will not give you a significantly different travel.
Also you really need to be careful about the angle of your cv's at full A-arm droop since at 45 degrees, as much torque is being absorbed by the cv joint itself as is being transferred to the wheel.
As far as needing a little more shock travel than your suspension allows, yes, you do need that for about 95% of the shocks that are produced. Bottoming or over-extending shocks can damage the seals in a relatively short time. Stock there seems to be maybe a three quarters of an inch extra (at full droop) but its not extremely important how much. There just needs to be some.
Once you know exactly what you want, if you can't find it, Bilstien and Doetsch both have a custom shop and can build what you want, and its not as expensive as you might think. I already know what I would like to replace the fronts with, I just haven't gotten around to doing it yet.
I have already replaced my rears and love them, but I think maybe Bilstein BE5-6252-H5 might have been an even better choice
The Vx, and IFS vehicles in general usually need very stiff valving.
Hope this helps. Andy