You can’t really go wrong with either one. If I had to choose right now I’d probably say Reno priest. Priest just got some of its core cards reduced by one mana, which makes it significantly stronger. I also think Reno decks are just a lot more fun because you can swap cards in an out and put your own twist on things. Priest has a lot of flexibility because it’s removal and board clears are so good
Cubelock is funny for me. I only play priest if its neccessary for a quest. I also hate pew-pew-priest. Cubelock with the Albatros also is good against highlanderdecks and it destroys a little bit the draw of the new miracle druid. Very funny if they try to pull maly with quest and instead they get a 1/1 Albatros or they draw one with the Witchwood pipers instead of karl.
Reno priest is more flexible in the wild meta, whereas cube lock jumps up or down. I think Reno priest is the more safe craft, esp since all the reno-esque cards, and all the anduin combo cards, are useful in other contexts, but cube lock's core pieces require other expensive investments to use elsewhere.
I would not craft anything for Wild until they nerf mage. The Highlander quest, Flamewaker Quest and Aggro Secret archetypes form a deadly trio which pushes everything else out. You can counter one of them but not all 3.
The answer to your question is easily Reno Priest. This is because by definition its roster has 30 unique cards. That means every expansion you can sub in a card for another.
In a way you are like a manager for a baseball team and you are overseeing the performance of the top 30 players you have on your roster. Raza is your Mike Trout and Kazakus is your Justin Verlander plus a few other stars but the rest are under your discretion. Thats the fun.
Cubelock is a lot more robotic. There's two of's and not a lot of wiggleroom. Also theres a new legendary coming that will blast through your voidlords.