Just to throw this out there. Pretty much every RDA made in the last coupla few years comes with a squonk pin. Unless you have really old ones, the RDAs you already have will squonk fine.
Then it's just a matter of a mod and you can get perfectly good ones for under 50 bucks and right now under 40. Or even 30 maybe

Many will use generic bottles that can also be had for a song. 20 or 30 bucks will get you several years worth at least. I buy em up when they're on sale for 2 or 3 dollars each.
Just to throw it over there

Squonking is good.
I spent my first few years as a vaper, back in 2010 through 2013, spending ungawdly amounts of money, chasing the latest, greatest innovations...many of which were unsatisfactory and went to waste. Without exaggeration, I spent enough on vaping in those three years to have bought a nice used car. In retrospect, I'm certain I was "throwing money" at the unfounded fear that I'd return to smoking cigarettes.
It took years to find what simply WORKS for ME. Once found, I stocked up. I have what's probably a lifetime supply in hand, at my age. Satisfied. I've done my playing around and have no need to chase the golden vape beyond the horizon.
I haven't spent a Dime on vaping since March, and see no need for quite some time to come. Those purchases were stocking up on items not immediately needed, from the '
Bargain Bin Treasures!' thread. Eventually, I'll need to buy some more PG...in another year or two. Possibly, I'll need to buy some batteries before that. Maybe a charger too, they don't last forever.
I smoked the same brand of cigarettes for 30-odd years, no need to experiment with other brands, because I found what I LIKED.
(oops, I actually DID try the rather pricey Nat Sherman brand for a while. Nice, but I'm not rich)
If you haven't already, you will realize that simply being active on this, or any other special interest forum, will cause you to buy WAY more 'stuff' than if you stay away more than you stay in. The forum for my make/model car had the same effect, to where "upgrades" neared the cost of the car.
I have no issue with experimenting, I love it! But, after you find a system that works for you, there's no need to stretch the budget trying this and that.
If I live that long, in ten years I'll be known as the eccentric old guy vaping on the antique APV.

Uhhh, I might already be there since I have functional ProVari 2.5's and a lifetime of Aspire Nautilus coils in stock. I also have some more modern mods, but I can always pull out the ProVari for old time's sake.
P.S. I once tried what was likely the first 'Squonk box', the Carlos Juice Box. And, that was nearly a decade ago.