Database Software

As we are planning to migrate our Prod database tier we have two proposal's

1) Migrating 6 databases to new 6 standalone server's ( Hp integrity rx6600 4p/8c)
2) Or The other one Migrating 6 databases to 6 node Rac cluster with same h/w above


like
SIX databases
--------------
- DB1
- DB2
- DB3
- DB4
- DB5
- DB6

Node1: (DB1 with instance DB11)+(DB2 with instance DB21)+(DB3 with instance DB31)+(DB4 with
instance DB41)
Node2: (DB1 with instance DB12)+(DB2 with instance DB22)+(DB3 with instance DB32)+(DB4 with
instance DB42)
Node3: (DB1 with instance DB13)+(DB2 with instance DB23)+(DB3 with instance DB33)+(DB4 with
instance
DB43)
Node4: .................
Node5: .................
Node6: .................

- I want to know which proposal is cheaper like licensing 6 database's on standlone or licensing 6 node RAC cluster ?
- can any one pls provide approx licensing cost's for both proposals and will there be any extra h/w or s/w which is more expensive to afford on RAC ?
- Is the 2nd proposal efficient (performance wise) ?

thanx in advance