Wilts and dorset are one of the main bus companies serving romsey and the surrounding area, with routes stretching from Romsey to Halterworth to Salisbury and back. Here are a few websites that might interest you:
A List of vehicles that are used by wilts & dorset
A list of routes that are operated by wilts and dorset
The homepage of the bus company
Current wilts and dorset bus timetables
A wiki page about wilts & dorset
Wilts and dorset have relesed many diecast models of buses in their fleet, such as one of the four remaining Optare Delta Buses or the Mercedies Benz Citaro.