For cheese, go to Paxton & Whitfield or Neal's Yard. P&W do a monthly scheme, I think, so your present lasts all year, or you could go traditional and send (the middle third of a) Stilton or a truckle of cheddar (I would love one of those). Anyway I am sure they l have plenty of gift ideas for you.
For chocolate H de C is OK but what about a Fortnum & Mason box of marrons glaces or something else traditionally Christmassy? Of course they sell delicious chocolates too.
For sis, give her a Jo Malone Voucher. If she doesn't find something in there that she likes, she is probably dead.
With the first of these suggestions, I think a large part of the fun of receiving them is the wrapping, not because it looks nice (though it does) but for the reminiscent-of-Bertie-Wooster joy of frequenting smart English institutions, even if not in person. Therefore, for your husband, I recomend:
- the recently published book of PG Wodehouse's letters
- something from Jermyn Street, ie a shirt from a v traditional shirt maker
- anything from Geo. F. Trumper
- Dr Harris' hangover cure
- an antique magnifying glass or map or other curio.
As for my DH, I am getting him a Bonsai tree, plus the kit to look after it. But now I wish i'd looked for an antique map.