You should be able to get a 25% royalty and a larger bonus. SEE an O&G Attorney before signing anything. The royalty percentage is significantly more important than the leasing bonus, although you should be able to improve both sides of your offer.
Don't be in a hurry to sign. Time is on your side--as the play develops around you, you will get a better view of what is there, and how much it is worth. NEVER sign the first lease they offer you.