2.0 fiesta st engine is a duratec. Supercharge it to 300 ish bhp pretty cheaply

Looking 300 for an engine and about 2k for a complete supercharger set up.

You ent getting 400 bhp out of any of the suggested engines for less than 4-5 k.

Cheapest way would be omega rwd gear box and Saab 2.3 red top turbo.