I have just bought my speedo and rev counter, really impressed with the Racetech one.
I plan to mount these behind the wheel so they should be fine for IVA as the sphere wont touch them, they do have a nice radius on to so should be good if need to mount centrally.

I'm trying to choose my aux gauges but can't quite work out what the IVA requirement is outside the specified zone, i.e. the middle of the dash.
Do they have to a radius of more than 2.5mm?

Would this pass?
http://www.carbuildersolutions.com/uk/fuel-gauge-kit

I was going with the non padded dash option

Any part which is contactable with the 165mm sphere in a forward direction has to have a radius of 2.5mm or more, unless it's under 3mm high. (it's things you could hit your head on if you fall forwards in an accident, basically).
I think that those cbs ones might fail - the bezel is 7mm high and looks quite pointy - but they might know if you ask them. Having to worry about a bezel is all a bit stupid really but thems the rules.

etb, stack, vdo, smiths all do iva friendly ones, there are plenty of others as well.