This is a very naive question but 1)given a compact Lie group G, is there a good notion of a sheaf of equivariant spectra on a G-space X analogous to the model structure that Brown develops in his paper on ordinary sheaves of spectra?
2)Is there a homotopy theory which allows you to take cohomology with coefficients in a sheaf of spectra and in which it makes sense to take for a G-space X the constant sheaf Z and recover Borel cohomology or "the constant sheaf in the equivariant K-theory spectrum" and recover K_G(X)?
3) Assuming answers to the previous questions, does the picture simplify in a reasonable way when one works rationally by analogy with the usual rational homotopy theory?