gareth moses

Hi all, needless to say im new here but i guess that's usually the case before you have one! Im 41 years old im relatively fit apart from an on going back problem and i weigh around 12-13 stone. I first seen a E rider ( http://eriderbikes.com/product-2/ ) which i was interested in as i desperately need some transport and i don't own a driving licence. I have also looked at an e moto ( http://www.allseasonselectricbikes.co.uk/shop/ ) and a iped (http://www.eped.co.uk/shop/iped-type-l/ ) Could anyone tell me which of these is best and why? My second choice apart from a E scooter/moped would be an Electric Tricycle, though if i got one of those i think i would buy a second-hand Trike from E-bay and fit a conversion Kit myself (Or have one fitted) as i would use it for off road use too (bumpy paths) and so would love some advice on the best conversion kit to get in regards to speed/power for hills and distance from one charge (I would like to get the best battery i could). My spending limit is £500-£900 Soo what shall i get a E scooter/moped? Or a Trike? and which one!! I would go for a Trike if i was sure i could get allot more miles per charge non assisted especially while carrying fishing gear i think..... esp if fitted with one of these ( http://www.tricyclesales.co.uk/Item/Accessories/Seats_and_Supports/Saddle_with_Backrest.aspx) Thank you all in Advance! Gareth.