Picking Carb Size: 950, 1000, or 1050 CFM?

So I plan on being able to (not frequently, but due to a 4-speed and very low gears) spin it up to 7,000 rpms.

It sounds like this is a street machine.And a manual trans is a special case.

Any 4bbl will rev to 7000 on that engine, on the street.
Even with 4.10s(a very low street gear), 7000 is about 51.5 mph, in 2.66 low gear. The shift into second drops the Rs to 5026 , and then you pull to 65@6340, and you are done.
Now, in first gear, that engine will be smoking the tires all the way, so the engine is not even working hard. Then, on the shift, there is a more than a good chance the tires will continue to spin, so again the engine is hardly working.
So lets say that engine puts out a lotta hp the dyno. That is working pretty hard, about as hard as it ever will.
Now on the street, that engine has a preponderance of power,and is never working very hard, so maybe it can breath just fine thru a 750. How will you know if it is too small? I know!; time it from zero to 60. Well since this is gonna be about 5 seconds, what if a 650 hits 5.04 seconds, and a 750 hits 5.02 seconds, and an 850 hits 5.01 seconds, and a 950 hits 5.00. You can hardly measure the difference. And Do you really care? I mean it's spinning all the way already! What's the difference if you ANNIHILATE!! the tires, or just annihilate the tires?

The problem with a big carb on the street is that the primary side is really big too. And sometimes metering at low rpm can be problematic with a 4 speed. But you have that kindof covered with the "very low rear gears".

But here's what I am thinking;
If you can't idle below 1000 rpm, and you have a 2.66 low in the tranny, and say 4.10s in the back, and say 28 inch tires, then your minimum roadspeed will be about 7.6 mph. Are you good with that? Well your 1050 might not be. And your 950 might not be, you might have to go down to a 750 before you can meter that low speed. The bigger the carb, the touchier will be the gas pedal. It starts to feel like an on-off switch;when it's not doing the rocking-horse dance that is.......
I've never had a combo like yours, so I can't vote, nor recommend, but I can advise for street; easy-does-it!