Your '65 will have a load-o-matic distributor that requires a carburator with a SCV (Spark Control Valve) in order to work properly, it also has old rubber parts (diaphrams/hoses) in it that should be rebuilt/replaced if you haven't already done so. If you ever wanted to go with a newer carb ('68 or newer) you will lose the SCV and you will have to upgrade your distributor at that time. If you think you will ever upgrade you should be looking into a few options at this time
All of the following distributors are 'dual advance' meaning they use vacuum signal from your intake (log) and not the distributor and will work fine with your current carburator, you should upgrade your coil to a 12V unit.
1968 or newer 200/250 points style distributor with a Petronix to make it electronic ignition
Both of the next 2 will require a Duraspark ignition box, GM HEI, or some other aftermarket ignition module like MSD or Jacobs.
1973 (guess) Duraspark distributor, Ford's first publicly available electronic distributor, it looks like a '68 with small cap
1975 and newer Duraspark II it has electronic ignition and a larger cap to help prevent 'cross firing' and was used until 1983 (when ford quit making 200's)
the Classic Inlines
DUI utilizes GM HEI ignition module, has the 12v coil built onto it, connect the vacuum to your intake (log) and a 12v feed from your ignition switch, set the advance and forget it. You can use it with your current carb, or upgrade to a newer style 1bbl, or even a 2bbl without needing to update your distributor.
I have a buddy that his '66 originally had a load-o-matic and we upgraded him to a junk yard DII with blue strain ford module then finally to a DUI and he said the DUI is the greatest update ever. According to him the DII with ford module was nicer then points but the DUI is the cat's meow.
If I had to make this decision (and didn't have any other parts to start with) and could afford it I'd go with the DUI.
-ron