Advice on first chain/cross?

Hey guys I'm looking into buying my first chain and piece. Im 5"10 slim build, and want something to showoff but also without being over the top. I'm thinking of a 14k 2 or 2.5mm diamond cut Franco chain, either 20 or 22 length, from jacoje jewelers, as it seems like he is trustworthy and has good reviews. I'm thinking if I tuck the chain in the front, it can still hit nicely from the side of my neck, and if I want to be a little more showy I can wear it out. I would be looking to put a 14k Celtic cross from myirishjeweler 1.1 high and 0.5 wide is the dimensions on the cross. Anyone have any advice on this? Should I go with a different length or width on the chain? Has anyone purchased anything from these jewelers before?