+1 on the above.
Your diff is attached to your axles which are attached to your wheels. The only way to gain clearance is to change the wheels - and anything beyond 50mm is going to be illegal in most states.
Suspension lift raises the chassis away from the axles. Naturally, the body is on top of the chassis so it will also be lifted. ABS & handbrake cables and hydraulic hoses are about the only things that need extending. The maximum suspension lift you can do is 50mm in most states without a certificate.
Body lifts are good for approach/departure angle and wading depth improvement. There's a bit of work involved in a body lift, since the radiator rises with respect to the engine (as well as the aircon, intercooler of course) and the bullbar will sit lower on the front. Handbrake cables, ABS sensor wires and hydraulic lines also need extending. I don't think you can legally lift the body AND the suspension more than 50mm combined without a certificate.
You can go larger than legal in any of these for road use but you need to get an engineer's certificate for it. Off-road you can please yourself as long as insurance covers it (that's for your own peace of mind). Certificates for large lifts involve lane-change tests and that usually requires hiring an area that is not a public road - often an airport runway.
Complying with the rules is less about fear of the cops and more about protecting your investment. Insurance companies don't like to pay out money and if they can avoid it they will. While there are stories of people who don't have claims knocked back despite illegal mods (making the vehicle technically unroadworthy) there are times when claims are refused - and worse, when the other side hands you the bill.
Personally I don't want to risk that because it could be expensive. Not only would I have to pay for my car's repairs, but the other car(s) AND all of everyone's medical expenses plus the compensation paid to everyone as well (and the legal fees). Compensation for a single person can be up to $450,000 (which includes legal fees of around $40-45,000). The bastard about this is it could be from an accident that is not your fault - someone else could run into you - but because YOUR car is not roadworthy, it can be argued that your car should never have been there, hence YOU are ultimately responsible.
