Engine swap? or mod the one I have. Suggestions appreciated.

[sdawg]

I have purchased a pristine 88 supra MKIII N/A, 68,000mi, 5sp, all stock from a lady that bought new. My intention was to find a turbo model but couldn't pass this one up for what I paid. I would like to have a MkIII that puts down 500rwhp but from all the info I have read that is not very obtainable modding the na, but very easy to get with the 7mgte engine. Would like to get everybody's opinion on the best way to get to that 500rwhp. I dont want to just slap together something and see how long it will last, I want as reliable as I can get. Should I find a 7mgte engine and do a full swap, or put a turbo on the na and see what hp I can get that way? If buying a 7mgte is the best way to go, then what all will be needed to do this correctly? This is an awesome car and I love it, just cant handle the lack of power with the na engine. All suggestions and comments will be greatly appreciated, thanks.