My comments are for recreational diving.
Sadly you need AOW and Nitrox far more that Fundies or any GUE training if you want to actually do a wide variety of dives. I was certified PADI OW in 1976. In the day, that training included decompression theory and gas management. there were no further certs (except instructor) and everything was learning by mentoring/doing. After 40 years of diving and 2500+ dives, with a significant percentage deeper than 100' and over 30 planned deco dives, I had to go get AOW and nitrox cards because, even with my logbook, many operators, in the Keys particularly, just would not take me to anything deeper than 60' or give me a nitrox fill. Dive ops who knew me were a different story, of course, but going into a new shop for a charter became a frustrating experience. I suspect insurance played a role (ie no coverage if they took someone diving beyond what "the card" allowed).
Simple fact: to be assured of actually diving beyond basic limits with dive charters, you need AOW and Nitrox. To do those dives well, GUE training can't be beat but it might not let you do the dives in the first place. We have wrecks where I dive that are 120 and the fundies card, it seems, will not certify for this--have no idea why as someone good enough to get a fundies pass is more than qualified for this.
So, my advice, get AOW and Nitrox right away. This is your passport to actually be able to do deeper nitrox diving on charter operations. THEN, take Fundies. Consider Fundies as solely for skill improvement to enable you to do those dives in the safest and most enjoyable way possible. Also, if you want to go tech, it is probably the best foundation you can have if you take it in doubles.
Especially if you travel. Do you really want to get to Indonesia or the Galapagos, or the Keys, only to find that no one will accept your GUE card?. It is sad, but it happens.