I need to rollover 2 accounts : Roth 401k -> Roth IRA 401k -> Traditional IRA Can I make both of these changes within a tax year?

Yes.  They are independent of each other if your 401(k) plan permits.

Also, how do I report these rollovers? If I change them to accounts with similar tax bases is there any tax liability? 

You will receive 1099-R form from the plan administrator to report.  If it is direst trustee-to-trustee rollover (as it should be) the 1099-R will have a code G on box 7.

Like kind rollovers [401(k) Roth to Roth IRA, and Traditional 401(k) to Traditional IRA  are tax free.

The Form 1099-R reporting the direct rollover from the Roth 401(k) to the Roth IRA would have code H.  The one for the direct rollover of the traditional 401(k) to traditional IRA would have code G.