What Bledlow said, especially on what works and doesn't work as rear lights. Static + flasher is the way to go. Anything brighter than a well-aimed Smart Superflash is superfluous in darkness (more powerful rears may make sense for being seen through bad weather in daylight). Surface area makes it easier to estimate distance/speed.
For a first-order approximation of what's what in dynamo lighting, have a look at the Busch & Müller range. The IQ Cyo (in its various flavours) is extremely popular around here, for good reason. Other manufacturers' lights are going to be in the same sort of ballpark performance-wise - standardised dynamos setting a hard limit on power availability, and LED technology being what it is. B&M's optics are generally considered superior to competitors for road use.
Dynamo rear lights tend to be moderate in brightness, well designed and fit-and-forget. They don't usually have flashing modes, as this is illegal in Germany/The Netherlands (where most are sold). Augmenting them with a battery-powered blinky is a good approach.
For hub dynamos, it's basically Schmidt (expensive, utterly bullet-proof) or high-end Shimano (much cheaper, extremely reliable). Some people get a bit religious about the differences, but I don't think there's anything in it performance-wise (a couple of percent of bugger-all drag is still negligible). Low-end Shimano dynamos are much less efficient, but cheaper and would be fine on a commuter bike. Other manufacturers like Shutter Precision are in the game, but the jury's still out on their reliability.
Bottle dynamos are an option, and will drive good LED lights workably well. They're noisy, cheap and can slip on the wrong tyres in wet conditions. They're a good option for exotica like tadpole trikes, and as an upgrade path if you can't afford the wheelbuild.
Dynamos can be used to provide power to charge batteries, given an appropriate gadget to convert AC to DC and regulate the voltage. The de-facto standard is a USB-compatible power output that will charge smartphones, GPS receivers and the like. This is a useful option for audax and high-mileage touring, but the amount of power delivered is relatively low. You won't get a useful amount of charge into your iPhone on the 5 mile ride to the office! Charger gadgets vary in quality, efficiency and reliability. Some are shockingly badly designed. Recently, light manufacturers have started integrating power sockets into their dynamo lights. This makes sound electronic sense, and works out much cheaper than both a light and separate gadget.
Dynamo lighting usually works out cheaper if bought from Europe, where such things are legally mandated and sold in bulk, rather than being a niche item as in the UK. This includes the cost of international shipping.
If you opt for dynamo lighting, you'll want to have a basic battery front light or head torch with you on non-trivial rides, to use as a light source should you have to repair a puncture or similar. A Chinese retina-burning 'main beam' isn't a bad companion to a dynamo system for this reason.