But I have the love cuff? What do you think
I don't see why not. I have 8 pieces from the same line at C (not LOVE though).
I don't think the others compare for a classic buy:
I think you should go to Bond St and try them all on. At this time of year, you may have to book ahead Cartier and Tiffany. Cartier Old Bond St is often less busy but less stock (more busy for repairs upstairs).
Bvlgari DD is nice but IMO quite evening - a little diamond in daylight won't really show. I like the onyx/rg version though. Try it on, but I think you may disappointed at its impact IRL. The chain is very fine, the little pendant is all you will see (see attachment) - but if you are very slim, petite or curvy it will look appropriate. The way the model is styled is perfect for max impact.
Tiffany Wire T does not do it for me at all sorry (and apologies to all that it suits beautifully)
Fope Flexit is also a classic look, with that little black diamond makes it a little edgy too. Probably my second choice. Can't see the necklace well and I don't know all the thicknesses/sizes, but I like that idea too if it's in budget.