if your set on a cvh then get the forged rods/pistons because you will want more power in the future, and 250bhp reliably wont be possible on std internals. may aswell get the basics covered first. then you will want a good managment setup, mfi is really stretched when its heading towards 200bhp. of course you maybe lucky and have an mfi system that can fuel for 230bhp without breaking a sweat but you will allways be questioning wether its gonna fail anytime soon. a good intercooler, radtec or grs will keep intake temps cool. a stage 3 t3 will be good for upto 300bhp. ported cylinder head and a good cam. the thing with cams is getting one made from good material as much as anything. seems to only be a few manufactures capable of delivering the goods these days. or you could drop in a zetec and bolt a turbo on, add a bar of boost and you have a solid 250bhp relatively cheap. a forged zetec with the appropiate bits will do 400bhp quite easily