If you can fit a Taurus or Mark VIII fan, use one of those, they blow about 3000+ CFM and can be bought for 20-50 bucks at a junkyard, but be aware they do pull ,more amps then most fans
I am running a Meziere WP 111. It is rated at 35 GPM. 55 GPM is only for big block, super high HP applications. With a 55 gpm pump, you might actually be moving the water through the system before it gets a chance to cool. I had to separately purchase the back plate and outlet fitting. Also, with the Meziere, there is no connection to your heater core. YOu can send the pump to Meziere and they will fit one for you for $30. I don't know if this is also the case for the CSR. Plan on buying a replacement motor to keep in your trunk for the day the electric motor on the pump dies on you.
As far as the fan goes, mount the pump first and then see how much space you have. Then get the biggest fan in terms of CFM you can fit in between the radiator and the water pump.
I bought a Taurus Fan to put on my Mustang a few years ago and it was too big so I put it on my Jeep. It definitely blows!
I ended up finding a thin SPAL 16" straight blade fan (2350 cfm) and it works great. My Northern brand radiator is the stock size for a '66 Mustang just a little thincker and the SPAL fan couldn't have fit any better. It easily keeps my 347 cool. I've got it controlled by a thermostatic switch in the intake as well as a dash mounted switch to turn it on any time. I would get the most powerful fan your alternator can take. Stock alternators won't take much either.
I used to have a Davies Craig universal water pump with my old 302. It was installed inline with the bottom radiator hose and worked great. It was nice to be able to circulate the coolant and turn on the fan after a run to get rid of all the heat. The only thing was the engine stayed cool for a long time so it took forever for the heater to work. I sold it when I put the 347 in because the pump was only rated for up to 5.0 liter engines. I think they do sell a bigger pump now though.
I have the Mezziere too, with a 2400cfm fan (I do not remember who makes it). All I had to do was mount the center of the fan motor about 1.75 inches lower than the center of the pump motor. Here's an outdated pic that sort shows it...