Personally, i would *not* put 302's with 914's. It'd be like pairing a Volkswagen Golf with an Audi RS4. They just don't belong together, even though they're made by the same company. The 914's need something like the 912's or 903's. The 300's just won't be able to keep up.
I've seen the 912's go for about $270/pair locally and they looked and sounded great.