Your proposed configuration - 2.0 litre, 5 speed, OME suspension and 225/70R16 - is almost exactly what I'm currently running as a daily driver - the essential difference is that I have 7 x 16 Grand Vitara alloy rims.
Suspension...
The OME suspension will not give you 1.5" of lift, it's going to be closer to 1.25" - installation is not difficult, assuming a reasonable level of competency and a reasonably well equipped tool box - you'll need basic hand tools, a good jack and at least two pairs of axle stands, a ball joint extractor would also come in handy. I did mine in my driveway over a weekend, but I could have done it one day, had I been so inclined - make sure to at least loosen the pivot bolts on the front control arms and rear trailing arms, and to retighten them with the weight of the vehicle on the wheels, as this allows the bushes to settle into the new resting position dictated by the change in ride height. I did remove the front control arms but some people say it's not necessary, if you have a long enough pry bar.
Gear swap...
You might want to re-check that gearing before changing anything - as far as I know the stock gearing for a 2.0 with 5 speed is 4.875:1 - block the front wheels so the car cannot roll, and jack one rear wheel off the ground - mark the drive shaft and rotate the tire exactly two full turns whilst counting the number of turns the drive shaft makes. My car is 4.875:1 and I find that works quite well with the 225/70 GrandTrek AT3s that I have fitted.
Assuming you can get front & rear thirds in good condition, the only special tool you'll need is a slide hammer puller, and there are ways to pull the axle shafts without that - the front axle banjo can remain in place - but you'll need to remove the right knuckle to get the axle out.
Let me know if you have any more questions ...