moira.
i bought the manfrotto 680 monopod, just for the 400/camera combo. like i stated it,s rated for 10 kg(22 lbs),so plenty sturdy. it,s black,4 sections,so tall enough for you,also has a wrist strap.i,ll have it at lambton,s woods tomorrow,if you,re there. got it at henry,s(oshawa) $79.00.was the only one in stock,but they have lots at their warehouse.
or you can get a sturdier tripod.mine is rated for 55 lbs. but i dont want to walk far with the tripod/gimball head/500 lens/ camera. it,s about 22-25 lbs to carry over your shoulder.
that,s why i went monopod with the smaller(400) lens.much lighter for walking.