This is 2 questions:
Question 1:
Can a stage 1 Archeops (PLB/NVI) evolve from a Stage 1 Archen (UNM)?
Question 2:
Can Fossil Excavator search your deck for a Stage 1 Archeops (PLB/NVI)? As of Unified Minds there is an Archen that evolves from a fossil, since Archeops says it evolves from...