id use a good heavy duty triple extension ladder, with stand off for extra ballance, ive had a eastern trading 3000wat vac, great spec, ALLOY poles are a nightmare at very high height, people are now using carbon fibre poles, i would recomend these.
you may find it cheaper buying seperatelly.
look through the web for gutter vacumms, dont take it lightly, you can damage guttering easilly using the heavy alluminium poles.
this was a lot of years ago, poles are getting lighter.
get a few jobs lined up first, as you may be stuck with them . no jobs coming in