hi, your brother can take the bus from Siem Reap to
Phnom Penh instead of boat or flight. Our bus trip was pleasant and comfortable but only thing was we walked long as the the siem reap bus station is a little away from the town. The cost was US$12 and we saw lot of villages along the way. nice isn't it? During our
cambodia tour we stayed 3 nights in Phnom Penh. There was a special offer on junior Suite double room in the month of June and the cost was $150.00 including breakfast. If your brother is interested then ask him to call them on (855-63) 964-301) and book the room. Convey my wishes to your brother!