vickster
Squire
You'll be able to use the Stirling on tracks, just put better tyres on it (the Maxxis are pretty crap) and moderate your speed, No bike offers everything for all surfaces, a flat bar hybrid or CX bike probably offer the best compromise - depends whether you want flat or drop bars
The Whyte R7 range have a good manoeuvrable MTB inspired geometry rather than being flatbar roadbikes. Personally I don't know what the Stirling offers for the extra over the Cambridge (older Cambridges can be got for a good discount versus RRP)
http://www.discountcyclesdirect.co.uk/catalog/search_results.php?searchwords=whyte+cambridge
The Whyte R7 range have a good manoeuvrable MTB inspired geometry rather than being flatbar roadbikes. Personally I don't know what the Stirling offers for the extra over the Cambridge (older Cambridges can be got for a good discount versus RRP)
http://www.discountcyclesdirect.co.uk/catalog/search_results.php?searchwords=whyte+cambridge