It really depends on a number of factors you haven't addressed. Do you have a windlass or do you pull the anchor up by hand and back? If a windlass then you need to know the best and maximum chain size that will go through it freely. You also need to know the amperage rating of the breaker feeding the windlass, because too much large chain plus a large anchor could trip the breaker prematurely during retrieval. Do you intend to have all chain or mostly rope and 25 ft of chain? Are you preparing for cruising in high wind locations or seasons, or are you a typical recreational weekend sailor?
In general you have three choices: BBB Grade 30 or Proof Coil grade. These are low carbon steel with low strength for the weight. They are the least expensive, and BBB will go through most windlass gypsys but PC may not because of variability of the link sizes within one length of chain. Next up is so-called High Test, or Grade 40 or G4 or HT. This is high carbon steel with twice the breaking strength of BBB. It is usually good to go through windlass gypsys, and you can reduce the link thickness by one gage compared to BBB. The highest grade is Grade 70 or G7 or "Transport". It has very high strength-to-weight ratio, but in some cases may not go well through windlasses because the links are reportedly in uneven sizes. It is also expensive. There is another type, and that is stainless steel chain, which is extremely expensive and may also have problems with some windlass gypsys, but is essentially rustproof.
For what it's worth I bought high test HT for my H356 when initially outfitting 8 years ago, and have been very happy with it. It still looks great and no rust. It was a good compromise between weight and cost, I bought a thinner gage than I would have had to with BBB or PC, it does not overload and flows through my windlass like butter.
