Hello, i do speak english and i'm good with solidity, have coded some crowdsale contracts. I'm sure i can make a contract that will fulfill your expectations. We can test the contract on the reinkeby network (and you can be sure that it work perfectly) before you release the payment.
Please don't think that my price is too cheap to be true... i'm from Venezuela so i need to bid low to get some work , things here are pretty bad.
Also, if you need more "complex contracts" i can help you with that.