I just lost my 2016 RW 420 to a fire

Wife and I will be staying with Heartland and once the insurance stuff is out of the way we would be ordering the 427.
My questions are can I add 8,000lb axles instead of 7k? I know they fit in the same pattern with no fabr needed
Can I add disc brakes as well as upgrade to 17.5" wheels? I did that on my 16 and I feel its a must
While we love the Black and Orange full body paint, can we do Black and Blue? I've heard that as long as it was a color in the past that most likely it would be ok
Although not likely to happen but have to ask, there is room to add a full bath to the 427 like on the 4200 Cyclone. Can that happen? Or at least give another 6" of room for that back toilet as I am 6'6"!
Oh and the Yeti package is a must.
Thanks in advance!