All of the pieces you mention are beautiful, but few would be worn together with what you already have as a natural pairing. I think that you can pair one of your pieces with one of the new ones on your list more easily.
For pairing your current piece of the RG Perlee pendant; this would be very beautiful with the new addition of the sweet Perlee clover bracelet, especially since they are both in RG. It could also be worn with the YG guilloche 5 motif if you love that more, even though it is not a matching pair, since the metal on the RG necklace is not very noticeable.
I would not wear either bracelet on your wishlist with your current frivole 5 motif bracelet. It could possibly work with a YG Perlee sweet clover bracelet if you would consider that option in YG. Since VCA RG is very pink and the frivole in YG is such a shiny yellow gold, those would be harder to pair. With guilloche and the 5 flower frivole bracelets, I think that that there is too much going on to combine them.
If you choose a necklace on your wishlist, I would not wear it with your current RG Perlee necklace. The most natural pairing would be the frivole 9 flower necklace with your frivole 5 flower bracelet. The pairing of your frivole bracelet would be a lot going on with a guilloche 10 motif necklace, but again, maybe I would be surprised.
Is your top priority to add a piece that you intend to wear with both of the two in your collection already? With at least one piece in your current collection? Or is your top priority just to choose the next piece that you love the most, and either wear it with another piece of jewelry or ad a coordinating piece later on?
I don't like to make suggestions for pieces outside of a specific wishlist, but if your primary aim is to wear your two current pieces with a new addition, I would be interested to know if you have any other items on your wishlist.
On the other hand, if you just want to add the piece next that you love most, regardless of pairings, I think that they all are beautiful and 3 of the 4 are somewhat statement pieces.