Is that the one with the melted wax TTWK? I didn't realise it was so good. DH also loves JD and has a birthday coming up, can you describe the difference in flavor?
Yes, the one with the red melted wax stopper.
Looking at my post, it comes across quite snobbish. But I get irked when people call JD a bourbon. It's like driving a Fiat and calling it a Ferrari, just because it's an Italian car. Not all Italian cars are Ferraris, and not all American whiskies are bourbons.
Makers Mark is, in my opinion, a massive step up from JD in terms of quality. The first thing he should notice is the smoothness. There's no catch in the throat when swallowing, and it doesn't make you feel like you want to cough. Just a warmth in the throat from the product. The flavour is hard to describe. A bit of toffee, and maybe banana, but it isn't sweet at all, not syrupy.
It should be drunk neat, or with ice but don't let the ice melt and dilute it too much. A good supplementary gift for the OP, if he likes ice (as I do) would be some whisky stones. They are reusable stone cubes that go in the freezer. You put them in the whisky to cool it just like ice, but they are stone so don't melt. When finished you wash them and put them back in the freezer for next time.
I recommended Makers Mark as it's a high quality product at a mid price point, around £30. Others similar worth looking at would be Woodford reserve or Knob Creek. Personally I think MM is better but that's just me.
You can spend over £100, but the step up in quality from MM to a £100 bourbon is not as noticeable compared to the step up from JD to MM.
Problem is it's so individual. Comparing MM with JD is like comparing a freshly caught and prepared Dover sole with fish fingers. But some people love fish fingers, and there's nothing wrong with that. So OP might spend £30 on something that her husband doesn't like. And he may prefer JD 
Anyway, good luck.