Linksys MR9000 vs EA8300

Can I ask what is the best over all router to have in terms of setup and maintaining updates etc.

I am split between the MR9000 (more RAM and Flash Storage) and the EA8300 (more support?)

I am new to all of this so please bear with me.

All routers get the same releases, unless there's a hw/SoC/arch specific bug ...

Read Support for the Linksys MR9000.

Unless you don't want to spend more than $30, I wouldn't get an AC device, today.
Def wouldn't get any of those new.

Can I ask what an AC(?) device is? If not recommended, what should I get instead?

Liked how the Linksys has dual bios, do any other manufacturers support this feature?

Also, how does 256MB of RAM compare to 512MB RAM in terms of performance and stability?

It's not not recommended, it's just outdated technology.

if you want the dual fw, the Netgear WAX206.

some yes.

it's the same, but if you run additional software on the device, more RAM (and flash space)
could be beneficial.