If you're looking at generator hubs and lights, you might find more options and better deals on the big European sites: bike24, starbike, etc. might have generator lights for better prices than stateside. You can also get the shimano dynohubs in 36 holes if you wanted to go that route but the Shutter Precisions are almost the same price as the best Shimano one so I dunno. I've been pleased with my Busch and Muller lights. The luxos U is nice if you have a phone or gps that can charge via the usb but I cheaped out and just got a IQ fly or something. that really lights up the road.

The one thing you might want to consider is indexed shifting, 8 speed index downtube shifters are still around but I think you'd need to find a clamp to mount them on since the bike in your pic doesn't have standard braze-on mounts. I tried friction shifting my 9 speed cassette and while it was fine during the day when I was wide awake it became cumbersome at night in the rain. Some people have better experience with that than I do but it wasn't something I wanted to fuss with. Bar-end shifters would be another option but they are more expensive and you'd still need a cable stop on the downtube for them, so that's a 20$ problem solvers part or if you have a co-op you could scrounge up a used dt shifter clamp or a cable stop that would work. If I had your bike I would just keep the claris crank but might upgrade to tektro brake levers if you have big hands, I find them more comfy than the smaller shimano ones.

I upgraded the wheels on my miyata 1000 so I could ride brevets without using the 40 spoke heavy-duty touring wheels that came on it and I think it's been a decent investment. I already had a dynohub and the lights on another bike that was my brevet bike but it wasn't as nice as the 1000 so I combined the two bikes. I'm going to use it again next season and hope to finish a full SR on it and am going to try a 1000K on it too.

If I ever get around to getting another frame that is lighter (and with vertical dropouts) I will move the wheels over to that bike and keep the 1000 for touring. I built wheels around mavic open pro rims, there are good deals on machine built wheels on ebay (velomine, etc.), you could save money and buy a set and get the front rebuilt around a dynohub and have the back stress-relieved and tuned up by a good local wheel builder, it might save some coin. I've done pretty good on my miyata but the bike isn't holding me back at this point, it's more my fitness and pot belly keeping me slow.