What's next for the panel?

Now that, for the most part, the canopy work is completed on my RV
(except for glassing and such), and fall is setting in, actual
construction work will slow for the winter, giving me a time to
regroup on this project.

I'm also doing some "numbers crunching" on this pay-as-you-go project
because the need to get going on the panel (not to mention buying an
engine) is becoming inescapable as the "next step."

Because I don't have a bottomless pile of cash, I have to be a bit
judicious at this point. Buy a piece, pay for it either in cash or pay
it off ove a short period of time, then buy another piece etc., all
the while continuing construction.

This is as opposed to just writing a giant check for everything (home
equity variable rate now is 9.5% and, like I said, it's a
pay-as-you-go project.)

I bought a TruTrak wing leveller years ago... bought the Whelen
lighting system a year or so after that... bought the little PS
intercom last winter.

Now I'm trying to get my arms around what is the logical progression
from here? I'm thinking I could buy the ELT and transponder now. But
that VAF group-buy on the Icom A210 has my attention. I'd also like
to get an AFS3500 at some point. And, of course, I still have a
yearning for a Vertical Power unit, which I assume has to be purchased
fairly early since it changes the way one "wires" one's airplane.

I know folks say "wait to buy your avionics until the last possible
moment," but that's not really practical in my construction sequence.

So in what order would YOU add components to your panel if you were
adopting this convoluted process?