Been doing some macro upto 1:1 for some time now and intend to really dive in to see the beauty in the small world

From all the lovely documented discussions here, I could gather one would need
A) Tube lens - would the Canon 55-250mm suffice?
B) Infinity corrected objective - CncScope 4x
http://www.ebay.com/itm/320601555906#ht_1512wt_952
Would this be ok to mount on the Canon 250mm? (since there was no mention on the site if it was infinity corrected)
C) Adapter to mount the objective in front of the lens like Rik mentioned in the FAQ section.
http://www.ebay.com/itm/Nikon-CFI-M25-m ... 285wt_1270
Found this here on the site, but would love a link to Ebay with the actual adapter (the Canon 250 has a 58mm dia)
Would love to hear inputs/tips on these

TIA!
Cheers,
Hayath