I like the flavour of Heineken. Hate Budweiser! Can anyone recommend a kit I might like?
To be honest, there's no real "magic" about the ingredients of a lager, the difficulty is all in the process. The classic Pilsner recipe is super-simple, just pilsner malt and a load of Saaz hops, so they're actually a good place to start making baby steps away from kits - see eg this thread, which is still way more complicated than you need!
https://www.thehomebrewforum.co.uk/threads/smash.96063/#post-1073774
There's two main differences between Heineken and Bud - Bud is about half as bitter (12 IBU) as Heineken and contains up to 30% rice which thins it out. So if you prefer Heineken that suggests you prefer some bitterness and an all-barley recipe. The esters of the Heineken A-yeast are also a factor, but we'll put that to one side for now.
The first thing is your water - lager needs low mineral water. Without getting too complicated - if you don't have problems with scale in your kettle (eg Manchester) then your tapwater is low enough in minerals to be OK for brewing, if your kettle furs up (eg London) then you will make better beer by buying in low mineral water like Ashbeck water from Tesco.
Both Bud and Heineken are 5%. You don't say whether you want an all-grain or extract kit - I suspect the latter? Anyway, it's easy to do the numbers if you do all-grain, as the numbers of kg in 20 litres is roughly the final ABV, so you want about 5kg of either pilsner or UK extra pale malt, or about 2.9kg of extra pale extract.
For 24 IBU, assuming a 60 minute boil you want 2g/l of 5% alpha-acid hops, so 40g of a 5% alpha hop like Goldings (Goldings is not "classic" for lager but a lot of British brewers are using them in lagers now). Adjust the amount depending on the alpha content - you'd only need 20g of a 10% alpha hop, or 80g of a 2.5% alpha hop (Saaz are often somewhere down there, so you need a lot to provide the necessary bittering.) I'd imagine Heineken uses a German hop like Hersbrucker, which might be 3% - so you'd need 40/(3/5) = 66.7g That would work well, as you could throw the rest of a 100g pack in at 10 minutes before the end of the boil.
Ideally you want to ferment lager cold - 8-10C is typical. But you can get away with cool room temperature with some yeasts like Mangrove Jack M54 and Fermentis 34/70.
So your DIY lager kit might be no more complicated than :
3kg extra pale extract or 5kg of pilsner/extra pale malt
100g of German hops like Hersbrucker or Tettnang
Pack of M54
Oh, and maybe some Irish moss or Protafloc to help clear it.
But it doesn't have to be much more complicated than that.