If buying most makes you would need the No. 6 downwards. On our Super-Lites we use a replacement top section which goes on top of the No.6 and then downwards.
You can then buy the Extra base sections, but good ones cost about £60-£70 retail, so they soon add up in cost.
We also make an addition to each section and then treat the top joint, which prevents sections jamming together, which in practice can be very annoying if it happens to the pole.
Alex