If anything leave the springs and drain 2/3 3/4 fluid. Should give a scale setup. Thats how I have been running my 10.2 and love it. Congrats on your new ride.
The only way to find out what is best is to buy all 3. 😁
On a serious note, I'm building an scx10. I have had a10.2 since 2017 or so, and I want a 10.3 and element enduro also. I love the 10.2, I've driven it brushed and brushless, and even abused it and it keeps on going...... for the most part...