From my experience I can tell you that banning Evocation is not a bad decision. Of course, the best offensive spells belong to the Evocations school, but you are still able to learn combat-oriented spells (the most common in general) from many other schools.
Banning Transmutation is instead more critical. The school is possibly the most varied one, and definitely is the one with the largest number of spells. This may hurt you more about using scrolls/wands/staves (at least if your DM usually give you random items), since you won't use quite a large amount of them. Transmutation is the perhaps the most versatile school.
However your choice is feasible overall. If you specialize, you have to pay the price of banning two schools, and there is always something you will miss. There is no spell which is 100% necessary, but almost every school has a key group of spells (e.g. Transmutation has all the flying spells IIRC) which you will be forbidden to cast. But I think you will be a perfectly effective Wizard even without it.