Flash for k70 ?

Hello wise people , I am an enthusiastic amateur , with a wish list bigger than my budget , i have just this week moved from Panasonic lumix bridge system to pentax k70 dslr and i am looking at flash units , I like the idea of the weatherproof pentax af540 fgz ii but not the £450 price tag , .....I'd rather save up for lenses than spend that much on the flash ...
Are there any weatherproof alternatives you know of ? No info I can see on the godox flashes on amazon concerning waterproofing ?
I'd be interested to know of suitable alternative I could use on / off camera with a sync cord or wireless trigger .
Thank you .
Paul .

If you can live without weather sealing get a Godox V1-P. Godox's wireless system is far better than the optical wireless used by Pentax and if you really get into flash photography there is a much wider range of flash and strobe options available to you.

Another vote for Godox. You can also look for Flashpoint which is an Adorama brand made by Godox. Adorama has better support. The thing with both Flashpoint and Godox is you need the "P" version of the flash (P = Pentax) so it will communicate properly with the camera.
I only know the Godox series off hand.
TT350 P which is tiny and about the same output as the Pentax 360 FGZ/II.
V680 III P which is a bit more powerful than the 540 FGZ/II.
The most expensive one is the V1P. It's a unique flash with a round head that more evenly distributes light and there's an accessory kit you can get for it as well that includes colored "gells" so you can change the lighting color, a grid to better focus the light, some diffusers and reflectors to redirect the light or soften the light.

Since I've gone Godox, I haven't looked back since it's a full lighting system that integrates with radio triggers and/or flashes that control other flashes with built in radios. There's also strobes for studio shooting and it's all compatible with Godox radio triggers. They aren't weather sealed, but for PENTAX, it's the best lighting system we have access to. The only down side is Godox recently stopped producing Pentax versions of their flashes. They can still be found brand new though and they're all cheaper than PENTAX equivalent flashes.

Yeah, if it has to be weathersealed it´s Pentax brand only.. but does it really have to be? Do you really shoot in the rain? Props if you do. Does it have to have TTL or HSS?
If not, get a couple of Yongnuo 560IV manual flashes and diy raincovers for peanuts. Wanna be fancy? Get a YN TX-560II remote controller for your hot shoe also. Still cheaper than a single Godox flash prolly. I do have a very lovely i-TTL Godox flash on loan from my friend for my Nikon, it´s great but I still rather use all-manual flashes.

My 2 cents.

Godox do have manual flashes too. I have a few of the Ving 850s that are fully manual.

And if using the more studio focussed strobes most users will probably do manual as well.