Yes, pick can select within the result of a shuffle in the same instruction.
And yes, there are vector literals, but restricted ones. The general mechanism is to use the con operation (reader phase) to get a scalar literal, and then the splat operation to make a vector out of it. However, certain popular constants, scalar or vector, are available from a form of the rd operation (reader phase). These are called popCons, short for “popular constants”. The selection of popCons varies by member, but all include 0, 1, -1, and None of all widths.
So for zero and None, assuming you have a bool mask to drive the selection, the code would be (for word element size):
rd(wv(0)), shuffle(<data>, <indices>), pick(<mask, <shuffled>, <rd>);
in one instruction.