Well the MAF you can check with a multimeter. I believe the resistances are in the FSM (or you can find it online).
Prob be a good idea to clean it too (electrical cleaner, do NOT touch it but you prob know that).
o2 sensor, you can go to sparkplugs.com or urdusa.com, get an OEM one! (no bosch, but you prob know that)

As for the pullies, im running urd idler, crankshaft and 2.2 ATM (going to break in the motor on the 5 or 7 psi then go to the 9 for this year). BTW there is a group buy on URD crank pullies right now and they wont be producing them again, theyve got them on sale for $250 for i think a week or two more if you're interested.
BTW more updated mod list in my sig now... argh you dont even want to KNOW how much this swap is costing me, but it's going to have the power of an LS1 and be all toyota sooooo.....