Yes, get the Woo, you will absolutely love it, I think the WA22 is an excellent choice: Silver or Black?
Once you get things set up and some hours on the PS1000's/WA22 and the good tunes start flowing, you will be so immersed in the music that all things technical will be far from your mind.
But yes, you can really fine tune the WA22 with some tube changes and I assure you from experience that if you do ever decide to upgrade, a pre-owned Woo Audio will sell in a flash and you will get the vast majority of your money back.
Congratulations on your purchase!
Edited by vinyllp33 - 8/3/10 at 8:12pm