Going into 5th with only 4 gears
I think a stock, orange 340 with the stock valve covers and all would look pretty cool.
That, or any engine with a more interesting valve cover/cylinder head appearance (Early hemi, W head Chevy, nailhead, etc.)
Congrats on the purchase! I want to hold a classic 'hot rod' at some point too, but I'll probably use a flathead for the sound and look.
Just my $0.02 :D