All of the options for watching Z with an English dub are flawed. Let's ignore the Fillipino dub of Z and Ocean Kai since they're not available as of this writing. Let's also ignore Speedy because, hey, it's fucking Speedy, the realm of bad audio quality, bad acting, and Engrishy scripts.
You're right about how the transition from ep 67 to 68 will always be jarring no matter what you do. The remastered dub of ep 68 being partial doesn't do it any favors.
Ultimately, the classic Funi Z dub post Saban was an edited dub first and an uncut dub second. Even the uncut releases had a custom OP and ED that would need to be swiped out in order to sync with the uncut footage. Ep 68-70 never had recaps that even tried to sync with the uncut footage, and it wouldn't be until ep 85 that the eyecatchs would be shown on the English video track. And of course the NEPs weren't even trying to sync to the Japanese NEPs.
The Remastered dub, inconsistent as it is with it's partial redub and alternate takes, at least tried to follow what came before it as well as try to sync with the Japanese. The redubbed narrator covered 68-70 for the first time, and ep 68-84 were given eyecatches synced to the uncut footage for the first time. On the other hand, the remastered dub is a mess. On the other other hand, Funi should have tried keeping in continuity with the extreme censorship of the Saban dub and not try to make an uncut dub that follows it. Going from "the Namekians are exhausted/hiding/etc" to acknowledging their deaths, among other things, is jarring in its own right. As long as you stick with an English Z dub, you're going to deal with a mess. I didn't even mention Westwood Z, which while not as extreme censorship wise as Saban Z is still more censored than any variation of Funi Z (possibly even the YTV cut, unless it shares the Westwood dub's avoidance at referencing death).
And of course, Remastered with Kikuchi makes things even messier, as we go with a soundtrack that was never meant to be paired with the sub. Sure, it brings pseudo-consistency with the Funi DB dub, but two wrongs and all that.
You're definitely right about Z (the show, not the dub) being the superior product when compared to Kai. Especially the way the Saiyan saga is handled. Kai cut some filler (like Goku in Hell, which conflicts with how Boo Kai kept it's Hell scenes for some reason) but not others (IIRC the media wasn't trying to broadcast the right between our heroes vs Vegeta and Nappa in the manga. If that's correct, it happening in both animes creates a big plot hole considering how ignorant the general public is about Ki since Mr. Satan got popular in universe). Unfortunately, you have to choose between a poor attempt at removing filler, or more abundant dub errors and a less accurate feel to the show.