As one of those difficult-to-buy-for men, I'd be very happy to receive a case (or a half-case) of red wine.
NO idea what you normally pay for a bottle - we tend to be in the £7-£11 bracket. If someone gave me six bottles of stuff in the £16 bracket, I'd be pretty happy.
That is to say, spend a bit more than you normally do (or he normally does) per bottle and divide up your budget to suit.
What types of stuff - depends a lot on what he likes, but in the £10-£20 bracket, it's hard not to get a decent bottle.
You can ask the regular drinkers on here for some recommendations of good wines that are a bit unusual, but here's one idea at around £10/bottle
Finca Las Moras Reserve Malbec 2016.
If he's a computer nut, don't even think about getting anything computery, unless you've asked for his suggestions first.
Having said that, I did just treat myself to one of these, and I'm sure any computery nut would like one...
Amazon.co.uk User Recommendation