I think whatever way you'll go, you'd end up with at least 30% power increase with the ability to have more (i.e. low boost turbo = 30%; higher boosting = ??% possibly up to and over 100% even). A basic turbo kit (chinese ones which is what I have) and gear will probably be a decent start if you're only looking for low to mild boost (5-7 pounds) to get rid of the rigs fear of anything slightly uphill. Adding an intercooler to it is absolutely not necessary at that sort of boost, so that is a major cost saving straight away - turbo/wastegate/actuator etc; manifold, dump pipe, sump modification for oil line, etc I reckon you could get your hands on for under a couple of thousand at the very worst. For fitment of that to the rig, you should only be looking at the same (or considerably less) through a decent mechanic and you have the desired outcome for a fairly economical price - with the ability to kick it up in the future if you should decide to do so.
Brands etc are not something I know, but that would be the place to start - basic kits ... QuickSpool do a proper Garrett bolt on kit for the Patrols starting at $3999 and they achieve around 480hp!!!