Engine Build Ideas...PLEASE HELP.

I dont think you will come close to 400hp for $2000

Not picking on you, but that isn't necessarily true, for one factory heads will support around 390hp @190cfm w/1.88 valves and around 420hp@205cfm w/2.02.
And with that, 2 It's all combo.
And 3, summit rebuild kit 9.1 comp.$360 or so dollars,MP cam& lifters $169 springs $89, timing chain $55, gaskets from jegs $35, rings $60, dist drv gear $29, $729+ tax [option 2.02 valves home porting$90=$819+tax]
Clean block & HEADS $80, Bore and hone w/trq plate $175, square deck $75, grind crank & $75-$90, valve job $175, balance $125, surface hd's $75 pair, install guides $110p/l, Seats + labor $140, positive stem seals $25 and cutting for them $40.
Reuse everything you can and clean your self=======$1929 w/o tax. these are average Machine shop/part cato prices where I live.