Lumix GX800

You should aware that GX800 (a.k.a. GX850 or GF9 in some regions) is being the entry class line of product among the Panasonic M43 Mirrorless Interchangeable Lens camera line up.

It is very cost friendly (should be around US$200 for the body + 12-32 nowadays), highly portable (the smallest Panasonic M43 except GMs), has majority of latest features that its larger brothers have, but of course at a trade off of less physical controls and are on more limited capacity. Its latest successor is GF10 (thank god, no more GX###).

Although GX85 (a.k.a. GX80, GX81 or GX7 mk-II in some region) has a similar name (once was very confusing), it is actually a class higher and edges more towards a full feature enthusiastic/mid range class of product. At a higher cost, larger size, but has more physical control (less Menu diving so faster operation), less limitation and above all, has IBIS which is great for run and gun video. GX9 (a.k.a. GX7 mk-III) is its latest successor.

There is also the G85 (a.k.a. G80/81) and its successor G95 which is a class higher than the GX85/9, and the flagship G9 (for still shooting) and GH5 (for video).

You have to live what it is capable of. In case if video is your major interest, a G85, which has a mic port for external mic could be useful to you.

Regarding lenses, GX800 uses M43 lens mount, such that any M43 native lenses can be used (mainly from Olympus, Panasonic, Sigma and one lens from Tamron. Also some Chinese brands like Kodak, Xi Yi and Yongnuo).

However, as GX800 is not IBIS, lens OIS is its only mean of stabilisation. You better pick an OIS lens (mostly from Panasonic) in case if you are shooting handheld.