Sure thing James. You could definitely buy a macro lens. BH is great, and has the best prices. How much time do you have to do this project? The reason I ask is you could try the macro extension tubes, and if you aren’t satisfied with the results you could then try the lens. I haven’t tried the macro lens, and all I have experienced is the extension tubes as far as macro goes. I honestly would recommend the tubes, but to further convince yourself, how about looking at videos on youtube with the extension tubes as well as the macro lens? That might clarify some things. It might be a lot easier to get good shots with the lens because of possibly not having to use the slider.
Can you explain xf or xha1? I was thinking 60p with the 5d would look phenomenal, but maybe you are working in a certain timeline with clips with different frame rates? I have worked with 60i in a Canon Vixia HFM301, and slow motion can be difficult to make look as good as a dslr. If you do 60i, I would recommend trying to bump the frame rate up so that there is less motion blur. That might work.
One other thing, do you have a zoom lens, like a 70-300? Tamron makes really good zoom lenses apparently, but just make sure if you use a tripod, keep Vibration Compensation (Image Stabilizer) off. The knob on the lens. Here is a link to this lens. I think a zoom might help, and there’s always those $1500 f 2.8 lenses hahh.
https://www.amazon.com/Tamron-70-300mm-4-0-5-6-Digital-Cameras/dp/B003YH9DZ4/ref=sr_1_1?ie=UTF8&qid=1389331441&sr=8-1&keywords=Tamron+SP70-300mm+F%2F4-5.6+Di+VC+USD
This lens was recommended to me by a professional photographer, and the video results are nice as seen on Youtube.
I hope this helps you James. If you have any other questions please let me know.
– Paul Harwood