Very neat little fun layout there Jamie
Regarding points and or extra track, it can be expensive to find here in Australia ( sometimes not) but in general its a heap easier and cheaper to actually buy from the UK on "the Bay" as it is cheap as chips over there !
Of course the currency exchange rate and shipping may work against you a bit, but in general if you shop around you WILL find bargains
Just figure out that Aussie shipping is likely to cost you $14-18 say 7-9£ and suddenly 15£ shipping for a stack of track at a few dollars a piece starts looking good lol
Happy hunting and if you get really stuck I might be able to help out some ..