my ka-t with almost the same setup with a smaller turbo, lasted 40,000km before i put her away and she still ran fine at that time. Changed the oil every 2,500-3,000. and Bing drove it numerous times.
the setup you are going for will be very reliable if your engine is good to start with. You will have to modify the sr downpipe a bit.
take a look at my ka-t project im selling, $1800 for more than half your list plus it comes with a whole chassis in decent condition. pm me if your interested.