Our standard ladder gear on a van is
Ramsey 2m Pointer - excellent ladders for ground work
Titan 3.4m - most normal houses, light enough
Titan 3.9m - only used on a few jobs now, normally WFP these.
WFP Poles
3ft - ground work and commercial shop windows
12ft - does a lot of first floor work
25ft - First and second floors
36ft - Town houses and commercial
Also have
Titan 4.5m for higher work, though very rarely used now, mainly for high gutter cleaning
56ft WFP used every friday for commercial work