Which is more Suitable Intercompany or Internal Orders?

Hi,

Could anyone give their opinion on these case:

I have these as a current setup 1 BG, 1 LE, 1 OU (200), 2 INV Org (200 Master n 201 Transactional INV).. now we r trying to have another OU (300) n INV Org (301) which belongs to the same BG and LE..

Basically 

OU 200 basically buys things from supplier and servers as B2B OU for our organization.

Now,

OU 300 basically buys things from OU200 and it has its own customer B2C (End users).

my problem is that which is more appropriate functionality should i apply? intercompany or internal orders? and could you give the advantage on implementing what versus the other?