help me flashing my k800 to k810

Posted by I.sabahi
Hi to all.I own a k800 and after a while I handeled with problems in Jave app.s and I have choosen to flash it.
I have ridden the helps & the ways to flash your phone.
this is ritten in my sofware info:
r8bf003
....
cda102568/6 r8a
cxc1250490 r8bf003

I have downloaded theese files:1:K810_R8BA024_FS_CENT_EUROPE_RED52.fbn
2:K810_R8BA024_MAIN_GENERIC_SM_RED52.mbn
i didnt succeed in downloading custpack cus I live in a developing country that I cant give mony for e.g. to TopSony.
can any body tell me another plases for downloading FREELY custpacks?
and have i downloaded the right main & Fs?
The last question:
my cda is:102568/6 ,this is my k800`s cda number. does the number changes when i flash it to for e.g. k810?aI mean does the cda of a particular phone changes after flashing(and if yes should I download the first or the second no. for it)?
thank you for wasting your time for me.sorry,Im really stuck in this situation and will be glad so much if any boy helps