The first diagram is your best option. The flow through the space will be much improved compared to the second layout. The 12' wall allows for an even larger vanity if you want one. Generally speaking, most tub/showers are 30 to 32" deep. You want to allocate 36" for the toilet installation. That leaves you enough space for a 72" to 78" vanity.

I agree with previous comment and use space near tub for "never enough" towel bars

I think the first option would be better and is what is more standard in similarly-sized bathrooms.

I know you didn't ask about this, but have you considered having a wet room instead of what I'm assuming is a tub/shower combo? It's always more pleasant to not have to shower in a tub, based on my past experience, especially dealing with a recent injury, and typically safer as well. You have enough room for it - you can gain some extra space by shortening the vanity and adding storage elsewhere if that is a big concern.
(The first pic has a double vanity, so you would have enough space by taking one sink out to fit that layout in this bathroom. The dimensions are apparently about 13' x 5', so your bathroom could be a version of this - just a foot shorter and a bit wider.) I also included a photo of an option with a similar layout and a freestanding tub.

By the way, no need to follow my suggestion - I just found this concept quite helpful in my past renovation.

I'm excited to see how this room turns out.