Doing a head swap isn't something to try for a first-timer IMO, especially if it's your daily driver as there's wiring involved which, while isn't complicated, can be difficult for some, myself included. Running wires, tapping pins, etc isn't always straight forward like turning bolts.
the y8 head will get you about 127 as noted above, no where near 200. if you want 200, you need to swap to a b with some work, an h with some work, a k-series, or turbo the d-series.
If you don't have any parts yet, consider a b-series swap. It's a little more complicated to wire up than the head swap and maybe a bit more work needed the hoist and axels, but you'll get better results for just a little bit more money (considering an LS swap as the price point)