Monopod advice (1 Viewer)

Recently got a 400 5.6 lenses (currently on a 50D body but likely to end but going on a 7d mk2) but on british dulls day no IS can be challenging so looking for something lightweight when i don't want to carry my tripod around but will support the weight (approx 3kg)

Recommendations will naturally depend on your budget.
The first thing is forget the weight ratings of various manufacturers as they are all over the place! Secondly I would go for as few leg sections as is practical. Mono pods with 5 or 6 leg sections look great on paper but the lower sections can get awfully thin!
For what it's worth I use a Sirui P424 (too big for your needs) which is very good and well made. If you can afford it my Gitzo GM2541 would be ideal. It weighs next to nothing, is rigid and will support pretty much any Canon lens going.
If the Gitzo is a bit salty (they are rather expensive!) then this Feisol looks interesting:
http://www.feisoleurope.com/feisol-monopod-cm1401-rapid-p-7.html
I have not used it personally but a couple of friends have Feisol tripods and they are very good quality for the price.

Happy hunting!