Check the forum traders for some of those parts.
The 040 and Z32 might be cheaper buying through the forum with either justjap or CRD than going directly to their websites. Go to the for sale section and see what they can offer.
Don't underestimate the stuffing around time with non-bolt on parts. I have used a HKS GT-RS on the stagea, they are relatively expensive but every nut and bolt you need comes with the kit. A true bolt-on.
On the R33 I have used a HKS cast manifold with a GT30 based turbo but you need everything from a new intake, new dump, machining of engine mounts, new pipework for the BOV, I had to move the carbon canister, had to fabricate a new heatshield for the manifold.....and more.
You either pay the turbo supplier for a bolt on solution or you pay your mechanic to make it fit.
I don't say this to talk you out of one path or another just go in with your eyes open. Lots of posts are written by people that say it is easy to do this or do that but by the time you have run around you are often well behind unless you can weld, have a garage full of tools and have time to spend under the bonnet.
Either way it will be fun getting it all sorted.
(For your power target the GCG turbo with OP6 housing (ie series 2 stagea, R34 GT-t) will make the level you are after, a G3076 will get there easily but with a penalty down low).