Hey Mlenox,
Your requirements and budget are going to drive your decision for all three of these items.
For cases, talk to Winni at goldenstarlaser.com. Good value from what I understand.
Flexmods P3s are sold out for a couple months while a new version is being created. Consider getting a driver from Badpip (a dual driver is the smallest he sells) if you require an analog driver sooner than that (You can find him on eBay. Products ships from Denmark).
For the galvos, that all depends what you want to do with them and of course your budget. Money no object are going to be a Cambridge model. Money only slightly a consideration are EyeMagics. OneStopLaserShop has a good selection of both Cambridge as well as the EyeMagics.
Great value for your money category are DT-40s, DT-40Wides or DT-30s depending on your needs / budget. Talk to Dave at lasershowparts.com. (Australia)
At the lower end, Chinese vendors such as Fang at Meirelight on eBay. (Assume you are going to get a bit less than you are promised in this price category.)
Several members on this forum can provide additional opinions and options if you specify your intent and limiting factors.
Cheers,
-David
"Help, help, I'm being repressed!"