not trying to be 15k in the hole with engine because of custom one off parts and things of that nature.
I'm not sure I understand what you're saying... you dont want to spend 15k on a motor??
When building a 500 hp stroker from scratch you can hit the 15k$ mark EASY.
Best "bang for the buck" on N/A high hp street motors would be something like one of these: http://www.ultrastreet.net/
If you think you can build an equivalent engine for alot less, you're forgetting to count alot of stuff