I'm curious about them and can almost afford the 40k ones, are they worth it? I'm a wand user.

Yes. Wand ougi from the original ougi card sets (1-6) are shit.

Any specific ones I should get? Is there a post somewhere that shows what they do and all of that? I can't seem to find one.

It depends on your set up. Wands have a 100% element scaling on skills (except for a few which have like 50% multi-hit) so depending on how much of an element that corresponds to the garg ougi that should be the one you get.

Example: I have around 112 ice element from magatama, ornaments and weapon. So it would be ideal for me to use Glacial Lance ougi on that weapon which is like 70% ice and 30% impact (or something like that) rather than the fire or lightning version.

In my opinion, don't bother getting Soul Reaper Scythe. Its super slow and its composition is like 10 slice, 40 dark and something else.