The 5146 that you have narrowed down should be the piece that you have in mind, well done.
Now what model?
The RG 5146 is just a sparkling beauty, possibly the most handsome version of them, if you like RG.
I tried the WG white dial, YG white dial on and the RG one (not all three on the same day certainly) and I must say the RG looks completely detached from this world: a very, very "dreamy" mood, timeless, "there can not be someting evil in this world, nice, all is well feeling".
Very, very sublime looking in RG!
Everything is warm, round, "soft", smooth ... a sunset that you can carry on your wrist.
I am nearly tempted to say it looks, I mean feels sweet - physically(!) sweet - like a child stares at a laboriously made lolly.
I personally like the 5146 too, as a casually elegant watch, in YG and slate grey dial best .
See if you can try one on, as it has also a very warm, noble appearance.
Not to interfere with your preference, but more as a fashion guide: a FORMAL watch is not complicated, small, thin and plain in design.
ONLY excemption that I would make is the: 5140 ... and now a very big SIGH ... a dream, an everlasting love ... PP master piece.
But you are looking for a dress watch that you can combine to business apparel, if I read your post correctly.
Besides the 5146 the 5396 could be a worthy option, here in both metal: in RG a classic beauty and in WG classy and very sporty!
Let us please know what you went for.
Regards
Moritz