Get an extreme 47 and 4 extensions.
That'll take you to 67'
Don't open all the extensions.
Use as many as you need and send back the surplus.
That would be very heavy. 4385g ! I think sl57 is the way forward - 2600g
I don't think the SL57 will be long enough. In my experience it's closer to 11' per floor.
And you need to allow for standing back from the building.
Just my experiences though-it may be just right-as has been said.
I had no idea the SL57 was so light, I've never used one.
The extreme doesn't feel 'heavy' though.
Let us know what you end up going for.