With that cam, I'm glad you're going with new springs. While it's not a super high-lift unit, it's a fairly decent duration. And certainly way more than the original one was, in both categories. Don't know about yours specifically, but most EB's didn't like to rev over 5000 rpm even when they were young. I'd bet there are a few that start running out of steam at 4000 nowadays. New springs are your key to happiness!
For the height, I've always just used a dial-caliper (most have an extension to check depth/height) to check installed height. There are specialized tools, but the dial-caliper has so many other uses that it's a worthy purchase if you don't already have one.
There is a specific tool to verify the spring rate at a given height, but it's a specialized one-use kind of tool. And though it's not 100% kosher to do so, most people just install the springs at the right height and call it good. Kind of trusting the manufacturing process and the Q/C people to send out only perfect springs.
I've used them, but mainly for checking the older valve springs during a mild re-fresh, or valve job where the cam was being retained.
And also more often way-back, when buying new springs through the aftermarket wasn't quite so easy and inexpensive. Which sometimes meant just going down to the dealer, getting stock springs and maybe shimming them up to gain a bit more stiffness and a few extra rpm.
This was not perfect, but cams hadn't changed quite so radically as they have in the last 30 years.
Trusting that the new springs are all perfect and consistent will come back to bite you once in a blue moon, but they usually are pretty good about being within the spec range. So if you get them set at the right height, you're "probably" good to go.
One of the more prolific builders here, like bmc and a few others, will hopefully chime in and say whether that's good practice, or if in fact they've run across a lot of bum springs in their experiences.
You'll also need a spring compressor tool. The nice ones for use when the heads are off can be fairly expensive, but you're going to be using one of the lever type for use with the head installed. Probably other types available nowadays, but most should be fairly simple and inexpensive. Relatively.
One more thing you'll need is a way to keep the valve up inside the guide. This is usually a simple fitting to screw into the spark plug hole and apply compressed air to fill the combustion chamber.
There are other types too, but this is the most common, probably the least expensive (other than just stuffing something in there!) and easy to use.
I think that's all the main things. Someone else will add anything I've missed.
have fun!
Paul