Request for advices

[cavajuolo]

Hi everyone and please sorry if this should not be the right place for posting this.
I'd like to buy a HDMI dongle but I'm a little bit confused. It seems there is a lack of a guide to help new users.

I have two "simple" questions:
1) which device do you recommend between MK809III and MK802IV?
2) which firmware should I install after buying?

Thanks a lot!!

[cavajuolo]

Thanks for you help.