Refrigerator fan noise

I have a new Cruisers RV TT with a kitchen slide out. It has a Dometic refrigerator that has a cooling fan that kicks on when it gets hot and stays on for quite a long time. This fan is really noisy and my dealer tells me that it's normal. I've also have heard that this is a common complaint with this set up. I've read that this fan is a cheap 12V 4" fan that can easily be replaced with a higher quality computer type fan with bearings instead of bushings. It's easily accessible but I don't know what fan I should buy. If you google computer fans, there are thousands of fans to choose from. The "quiet" fans are slower and don't push as much air so may not be as efficient as a high speed fan. I understand that the faster the fan....the more noise they make. Anyone have any suggestion on which fan I should try?
thanks