I prefer the Link series over the Aquaracer. I personally feel the overall look is more finished; but that is just an opinion. Tag offers both models in both blue and black, so if you prefer blue, you can still get that with the Link series. I think blue or black works. Black is probably a more versatile watch for day to night usage--but blue is classic as well.
Tag makes quality watches, your husband is going to have a nice surprise for Christmas.
Diana