Richard,
For panniers, look at ortlieb -- something like the back roller classic or really anything in their line. Some people flinch at the price, but they are completely waterproof, will adjust to securely fit any rack (i've seen them on a city commuter, there's no reason interceptor would be different), hold a ton or roll down to a smaller size and will outlast most bikes. I'm pretty sure they make handlebar bags too if you want that. Arkel is another good brand for waterproof bags, although I like the attachment systems on ortlieb's a bit better.
On lights, for headlights I really like the B&M Ixon IQs that I have, they work really well and last a long time on 4 AA's (I use rechargeable AA's). Look at Peter White's web site and you will find a ton of info on lighting and good brands.
For panniers, look at ortlieb -- something like the back roller classic or really anything in their line. Some people flinch at the price, but they are completely waterproof, will adjust to securely fit any rack (i've seen them on a city commuter, there's no reason interceptor would be different), hold a ton or roll down to a smaller size and will outlast most bikes. I'm pretty sure they make handlebar bags too if you want that. Arkel is another good brand for waterproof bags, although I like the attachment systems on ortlieb's a bit better.
On lights, for headlights I really like the B&M Ixon IQs that I have, they work really well and last a long time on 4 AA's (I use rechargeable AA's). Look at Peter White's web site and you will find a ton of info on lighting and good brands.