I have EF adaptor and XLH1, but not sure what lense I should be considering when trying to achieve what letus for canon achieves? anyone has experience? or are they totally different animals all together? :)

COMPLETELY different animals ...

The EF adapter will allow you to mount EF lenses on the XL, but because of the chip size difference between the XL and a Full Frame sensor, there will be a magnification factor of 7.2. So a 50mm Prime will really be 360mm on the XL.

It's only really useful if you need long telephoto reach.

The Letus adapter will provide the cinematic DOF you are looking for.

Hope this helps.