There are a couple of reasons why I'm pairing a whisky based cocktail with 'Gin and Murder', the first being that gin feels in bad taste being the drink of choice of a central character who is an alcoholic. The second is that I consider the Rob Roy and its cousin (the Manhatten) a brilliant cocktail party option, and this book more or less opens with a cocktail party.
Originally published in 1959, 'Gin and Murder' is well worth seeking out. Josephine Puillein Thompson is better known for children's books, but this one is very definitely for adults. It gives a brilliant description of the 1950's county/horsey set, as well as the damage that alcoholism does in a portrayal that's both brutal and sympathetic. It's more usual to see excessive drinking glamourised, so this portrayal is important in a bit of lightish crime fiction. It's also an intriguing mystery - so wins on all counts.
The Rob Roy is half and half scotch whisky, Italian (red) Vermouth, and a dash of Angostura bitters shaken over ice and strained into a cocktail glass. Get a good vermouth (cocchi or cinzano 1757 rosso are my current favourites) and a decent blended whisky. I like Grouse for this, but keep meaning to try it with something a bit smokier like Johnnie Walker Black Label. Whatever you choose, with so few ingredients they need to be good.
Which brings me, possibly not for the first time, to some observations about hosting a cocktail party. I have known houses with purpose built bars in them (my grandfather had one complete with a sink and fridge - it really was a bar. We thought it was tacky, and it was, but I kind of see the point of it now that both he and it are long gone) but it's not common. You could make what you liked, as you wanted it, and had somewhere to clean equipment as you went along whilst still being part of the party.
Without that luxury one option is to make batches of cocktails beforehand and keep them in the freezer - perfectly sensible and a lot of the classics (like a Rob Roy, or any sort of Martini for example) are perfect for this. There's some specific suggestions in 'A Spirited History of Vermouth' along with some bar tenders tips as well.
Whenever you make the drinks though, the key is to limit the choice - otherwise all your measures, shakers, stirrers etc need washing between each drink which is a massive nuisance. Another advantage of limiting the options is that you're less likely to end up with a lot of sticky, bottles half filled with things likely to deteriorate horribly before you get round to using them again, and it's easier to control the costs.
I've seen a lot of people blow hundreds of pounds chucking a whole bars worth of spirits in a shopping trolley over the years, and whilst I'm not complaining about the spend I really do think less is more. Pick something to build your drinks around - in this case a good Rosso Vermouth, choose no more than a couple of options, make them well, and minimise the work you create for yourself.