Hi! I'm also not sure what your best choice would be. What was your DH's count/motility, etc?
My DH has a VERY low count (although we do have a 20-month old son who we conceived after just 6 months of trying) and he is on a lot of supplements (listed above in Infertility Tricks). He also just had a varicocele surgery on 9/10. We were told we could start BDing again as soon as he felt up to it...only a few days in his case
I did give up coffee when we were TTC #1 and I got pregnant a few months later, but I have no idea if that helped or not. I have heard that coffee can make your CM more acidic, so maybe it's worth a shot. (I've actually just started drinking it again

since I've given it up for almost a year while TTC #2 with no results). As far as your DH, too much caffeine is not a good thing, but actually drinking caffeine 30-60 minutes before BDing is said to speed the swimmers up...even my doctor told me that.