As Steve said you need to ascertain the basic health of your engine before you go speccing up parts. The rail and plenum are not necessary with low mount internal gate turbos. Stuff like the oil pump you'd do in conjunction with a rebuild rather than off the cuff.
As far as shops go gut feeling counts for a lot - and whether you get a good vibe from the people you're dealing with.
Oh and as a parting comment - stock RB26s work for 10 years or 100,000km - rarely both...
Jash