Is the machine shop equipped to put the proper convex surface on the lifters? With the problems people have had with lifters and cam failure the last 20 years you want good component match. IMHO the best bet if ordering the Isky E4 is to get the matching lifters from them. You do not want to take a chance of wiping the cam and having to take the engine apart again.
Another little tip from Brian Salter Racing Engines and David Vizard, is to round off the bottom edges of the cylinder bores a bit. It is kind of like the rounded or flared horns or velocity stacks on the intake. Consider this, as the piston travels up the bore at 2,000RPM, the air and oil mist follows the piston up. A square edge creates a flow restriction which reduces HP and fuel economy, efficiency. It is not much, but everything helps. This needs to be done before the short block is assembled, as you know and should you decide to do it.