I'm with you.
Every day class is in session, learning never stops
If you have always wanted a hemi, and a block is available to you...or if you have no problem grabbing one of the Callies blocks that are available now.....my main advice would
be that you really should seize the opportunity as long as the expenditure doesn't cause any stress.
Even if you only have the chance to acquire a good 4.500 bore-capable block and can't do much of anything else for a little while, you should at least get the block.
If it's a good part, and you change your mind later, they hold their value and you can always sell it.
Heading down that road, iron might be easier to sell to street and resto folks (maybe a bigger market), aluminum might be easier to sell to racers.
I tried to give the whole big inch street hemi situation a push with a build thread, but I think about 8 to 10 people were interested in it, and it was mostly just me talking to myself.