TL;DR at the bottom
I've searched not only Mazda3 forums, but also Fusion and MX-5 forums to help me out and none of them are clear enough for what I'm finding. I need help because I need an engine as soon as I can afford it.

My 2.3L has horrible piston rings and I was quoted $5K to fix, and from what I can find, an engine swap is a much better option and not only cheaper, but more power! I've never done an engine swap and I'm doing this out of necessity. If it's easy enough, I can do it myself, but if it's safer to have a shop do it, I'm willing to pay up. I'm looking at specifically the 2.5L i4 from Ford/Mazda. I need to know which engine from any and all years will be the easiest to drop into my 2006 Mazda3 S hatch, as in as little work to be done to it to function as normal with the stock ECU, hosing, TB, etc. I also want to know the differences between Mazda 2.5s and Ford 2.5s (if any) and what years are the best and from what car is best to order from?

TL;DR
- '06 3 hatch w/ ****ty piston rings. $5K to fix
- Engine swap to 2.5L is cheaper & the better option, BUT
- What's the difference between Ford & Mazda 2.5L?
- What year 2.5L is the best?
- Which is the absolute easiest to use for this swap & will work with the most parts in my Mazda3? i.e. stock ECU, TB, wiring, etc. Minimal need to swap parts from both engines
- Part No.? How to find & where to buy in CA
- Must be able to pass CARB & BAR

Please and thank you!