Can I just use any old single crankset for a Shimano Nexus 8, or am I missing something? I'd rather not use a crank that looks like it's from the future (as the Alfine crank does).

You can use any crank that'll take the size of chainring you want.

I Pretty much have stayed with square taper BB Type cranks , so the Chainline with that IGH single cog is a BB spindle length choice

I have doubles , disc chainguard ring on the outside [Trouser leg protection] , Chainring (Long wearing:Surly Stainless steel) on the inside .

Yes you can use any old single chainring. The bash lip is not necessary. Steel teeth will last better.
I have been using A White industry ENO aluminum crankset for 8000 miles I think. One ring wore down too fast IMO.
I had to put the old chain back on.

After Fietsbob's post I feel I should add "and can put it in the desired horizontal location" - singlespeed chain setups (including IGHs) need the chainring and rear sprocket to be lined up properly, in other words you need the correct chainline.

Most SS cranks are still square-taper anyway, and if you're buying you can just get the desired chainline by also buying a BB with an appropriate spindle length, as Fietsbob said.

Thanks all. I'm working from a bare frame, so I'll just find buy the crankset first, then install the appropriate BB to maintain the correct chainline. Any further recommendations on fluted cranksets, either classic or new, are welcome. I love the look of the VO sets (who doesn't?) but they're a little spendy.