The EKK1 kit is fine... many many people go this route. I would imagine that this kit gets purchased more than the EKK2 kit for the simple fact that it is the less expensive route, they are simple to install, and they satisfy a majority of consumers needs.
The difference, though I have never actually measured, seems to be an inch or two at the most rearward using the EKK2 kit. You do get better axle alignment and slightly better hood clearance but no better ground clearance. The hood clearance is better because the hood-line slopes forward and being you are moving the engine back... you gain a little.
If you have "worries" about oil pan clearance dont do the swap or RAISE YOUR CAR. If you like to roll around in the weeds this swap is not for you! I like an aggressive stance and I hate gaps in the fender well so I opted to run the less popular 17 rim to gain some ground clearance and fill the fender well without dumping the car, damaging suspension components, and sacrificing ride quality.
Fallowing measurements will differ by tire brand...
17" w/ 205-40-17 = 23.55" overall diameter
16" w/ 205-40-16 = 22.45"
15" w/ 205-50-15 = 23.00"
Either choice you end up making will be fine. I've seen both kits used on RHD's
Not easy and no way... you would be the first person (I know of) that went dry sump to avoid clearance issues in a street car. The process is drawn out, elaborate, and expensive. The parts are bulky and there is very little room to run all the equipment without making adjustments and compromises to where other items are located.
