for 4-500 you could probably get whatever. Just make sure it has at least a Dainite sole if not a commando sole.
I think one pair of boots that goes with a parka, a bomber and a topcoat might be pushing it but maybe not. Feel like an acne longcoat would go good with some chelseas or something whereas you might as well just get some docs or doc like boots for the bomber and shield jacket.
In fact you could possibly get both some dainite soled chelseas and a pair of docs with commando soles for when it gets really grimy for about 500.
http://www.jigsaw-online.com/products/s ... boot-11350 these could be well under budget.