Ronbo, a point of clarification if I may. A Pond block or a Shelby alloy block are a fine choice, and NOT to be compared to a Honda power plant!

The point is, a date coded 1965 'real deal' side oiler is very rare, like obtaining the holy grail if you would. The point was in specifying a 'superior replica' build does not mean 'anything goes', just because it's a replica. Some cars, like this one, are built to a higher standard of accuracy, which is uncommon with most of todays builds. That INCLUDES Kirkhams! David K, has mentioned several times he rarely finds a customer today who WANT original specs. Because of that the price for those specs have gone up a bunch. It's cheaper to buy 'billet' stuff now than original parts.
I think you would be hard pressed to put together a new Kirkham with these specs for under a $100K. If you did it's gonna take a lot of time, energy and money to pull it off. Much easier to simply build a 'modern' Kirkham utilizing the typical available parts: Billet suspension, Baer brakes, alloy Shelby block or a 428, etc. would save a bunch over an original side oiler, suspension, brakes, etc.
Is a modern Kirkham spec'd car faster, handle better, ride better and is more reliable? NO doubt, but then again a bunch of modern cars can say that. A bunch of replicas can say that as well. But THIS Kirkham captures the soul and spirit of an original like few replicas do today.
But maybe your right, maybe you could build to these specs for under a $100K, if your well connected and do some digging for the right stuff.