Forged kind of matters, but really only matters if you're looking at cheap crap in box stores--ignore that aspect.

Full tang doesn't matter for quality unless you're going to abuse the knife or use it as a meat cleaver. Don't chop wood with it and you don't need a full tang. None of my my knives over $300/ea have a full tang. I think I own one knife that I like with a full tang and it's a petty, where that feature doesn't matter.

Sets are a waste of money. Steak knives can come from somewhere else and probably should. They take up space in the block. Personally I don't like blocks, because I don't like a piece of wood telling me what size and shape knife to get, so I use magnetic holders, but if you want a block the Kapoosh universal blocks are great.

I avoid German steel knives except for Victorinox. If you're getting a German steel knife like a Wusthof or a Henkel, you're getting a soft steel, and if you're getting a soft steel there's no reason to pay for anything forged, because you're losing much of the value of forging, especially in a stainless blade. For my money I don't see any reason to pay for anything better than a Victorinox Fibrox until you're willing to either get into at least an entry-level Japanese knife or carbon steel. I'm completely unimpressed by Wusthof and Henkels across the board and would never buy them again--that was fine for me as my first knives as a teenager but not as an adult.

A Santoku is an alternative to a chef's knife, and that's fine to have both--often it ends up as a his and hers if you get both.

There are basically a bajillion buyers guides to knives like this on the market. Google this and don't be lazy.

It's a wedding, so personally I'd get greedy and ask for more indivdual knives rather than an expensive set and hope more people added them up together, and I would register somewhere better than Bed Bath and Beyond, because their knives mostly suck. BUT, if you had to...sigh...if you HAD to....

You need a sharpening steel. It doesn't really sharpen, it just hones, but that's a longer response.

You need an 8" chef's knife or equivalent Santoku--the Santoku can be smaller. The best mass-market cheap one is the Fibrox/Victorinox one. The best bang for your buck expensive one without going to a Shun is the Calphalon Katana 8". If you're spending real money don't get a shun, get a Tojiro DP. Alternately, if you're feeling frisky, you can get a CCK 1303 cleaver, which will blow all of the aforementioned out of the water for only $60, but they're carbon steel, they're chinese cleavers, and they're not western knives or traditional, so people won't recommend them, but I use mine more than any other knife in the kitchen despite it being by far my cheapest knife.

You should get a bread knife. It doesn't need to be expensive, but it should be fucking long. If you want to spend money, the Richmond Artifex and Tojiros are the best, otherwise get a Victorinox--nothing else is worth spending more money on.

A long slicer is nice. A cheap long 10" granton Victorinox carving knife is nice.

A petty is nice. If you want cheap, Victorinox. If you want nice, Tojiro DP or Calphalon Katana.

You don't really need anything else, but if you added other knives the first one I'd add would be a filet knife, then after that you'll know what to get because it will get specialized. This is VERY abridged, but get your knives at Chefsknivestogo.com instead of BBaB.