I agree with Homerepairguy, the house wrap will do very little (if anything) for a block construction.
Hayzee has a good idea with filling the concrete blocks with vermiculite if you can get access to the tops of them, vermiculite is cheap, make sure you get it from a pool wholesaler, I built an inground pool last summer and the price of a big bag of vermiculite was between $7 and $25 for the exact same thing.
Blown in attic insulation offers about R3/inch so @12" you have about R36 in your attic, most places now are R49 for attics.
silver faced rigid insulation offers about an R7/inch
vermiculite is about R3/inch
drywall is about R3/1/2"
insulated siding about R4
if you could do the vermiculite, insulated siding and the 1 1/2" rigid siding a total of approx. R17, you would be over what is code compliant for external walls.
Hope this helps
