Don't feel ashamed to ask the owner for a raise if you feel like you deserve one. Change your perspective. They should be ashamed that they haven't been trying to do their best by you. And if it does come down to hurting feelings... who do you care more about, the owner or your wife and kids?
Also, the company has no obligation to you. They could fire you a day after giving you your big raise if they were suddenly short on money, or if they decided to cancel the product you were working on, or if they just felt like it. Why should you have a commitment to them that they don't have to you?
At any rate, the conversation will not be “fresh in mind” after two years. Six months, maybe... one year, just barely possibly... but not two years.
Ask for the bigger raise.
Besides, if you negotiate a raise and then leave, it means that they don't have to pay you that raise after all, right?