So it seems you will be running 45 mm track gauge Lez 2000, at least for starters. Now the fun begins.
If you want something robust where there is an off the shelf track item to deal with just about any track configuration requirement then stay with a code 332 rail based system that your started set uses, as there are a host of compatible systems for it out there. If a nearer scale track appearance is your thing then go with a code 250 based system. Yes you can mix and match with different rail codes but it can be a bit of a faff.
There are even some suppliers out there that can provide you with dual gauge 45/32mm track in either code 332 or 250 rail, points and all. Now I'm just being perverse. But it can appeal to some who run stock that scales correctly and is made for 45 mm gauge and also run stuff who's correct gauge is 32 mm, but similar scales. I run US Fn3 and UK 16 mm scaled items, I should be a natural for that combination approach but as my 16 mm stuff can run on both I stuck with 45 mm
Max