Your power expectations seem fair.
Personally I'd buy parts indivually.
Even good Kits have issues. For example I baught a racetech kit. It didn't fit then the turbo was faulty and the manifold kept cracking was awful.
I would splash out on a decent manifold. You want a good strong 3mm walled manifold. Not one of these flimsy shiny eBay ones, they will crack constantly and be a pain in your arse.
Reliability.. you can make a reliable turbo setup. But turboing a stock engine you always going to be waiting for the day it goes pop imo.
Maybe it never will and it will be fine. But it's a ticking time bomb, but if mapped properly and looked after at that power could be fine for many years. But if it does pop take it as part of the fun and fix it.
Shopping list. Well you need a turbo. Something smallish.
Manifold, wastegate, downpipe and exhaust, fuel pump, injectors, ECU a p28 to start with and a hondata s300 if you want but not required, a clutch, Oil feed and return lines. bov if you want one. I don't bother personally with bov. And an intercooler and pipework.