Yep, I can definitely help with the dump/front pipe, and most other mods you require. Are you in Melbourne? PM me if you like for pricing.
Hypergear can do some great rebuilds for the price, (he is the guy listing the rebuild on ebay.) Good strong product and service. There are other options available too, but their prices can vary from reasonable to expensive. You need to keep the turbo wheel size small if you want the car to behave on the stock map (without tuning it.)
There is a thread dedicated to the AFM failing, believe me you will know what it is if it happens. It is the same part as the early WRX and a few other cars (not the VQ35) so a quick google with the P/N will find you one for around $150 I think.