can i use a non-myfaves phone with my my faves plan

i have a samsung sgh t-329 which came with the my faves plan and i have a samsung sgh d-807 which is a much more sophisticated phone and i like it so much more than the limited t-329 clamshell.
can i use my already unlocked d-807 with the my faves service?

the d-807 doesnt have the firmware to use the my faves display. will i be billed for those calls to those five numbers as anytime minutes used? or as free?

Once again you've been so very helpful.
Thank you very very much!!

I have a D900 which does not have the myFaves, but I went throught the tmobile.com and I was able to set them through the website.

There is no unofficial problem with this being done. I have zero problem offering customers myfaves plans on non my faves equipment so long as its not an older T-mobile phone. Unlocked phones would be your best bet. Its the smartest move to be able to use the plan. While as its been stated, you won't get the T-mobile interface you can still manage the myfaves online and from T-zones.