I've heard a lot of bad things about the Techzone electronics. Specifically, issues with soldering and missing/wrong components. For an electronics novice, I think double-checking everything would be on the harder side to do.
That said, last I heard Mendel-Parts were still closed, but expected to reopen soon. This would delay you purchasing anything.
Also, the main issue with other electronics like RAMPs and Gen7 is that the Pololu A4983 carrier boards are out of stock at most places. This is supposed to change shortly (production delays).
This means whichever way you go, you're stuck with a delay, or with something you'd want to double-check to ensure it's correctly assembled. None of this is an ideal situation.