I personally dont like a ratio that high. reason being is that it takes about 12 months for base rock to become "live" enough to do the same amount of good as an equal sized peice of live rock.
That being said at the start your rock would only be about 50% effecient and at 6 months it would still only be about 75%. If you went with 25% base and 75% LR you would do better in the begining. With this being your first tank I would suggest the latter. Otherwise the mistakes all beginers make will impact your tank more than need be.