The temp will be between 20 to 25C, the nightlife is in the nama bay area some of the hotels are fair distance from this area, this site give you a idea of the area and hotel locations

http://www.goredsea.com/en_streetmap+1-sharmelsheikh-destinationstreetmap.aspx

if you go to one of the larger all inclusive the night life is in the hotel ,its rather a case of is this a family holiday or a lads one

It's really two choices. Either go for one of the large AI's that are outside of Namma Bay and can be anything up to a 25 min. cab ride in. Then you will probably stay hotel based and have one or two of evenings out in NB or Old Sharm.

The other choice is to stay in one of the Bed and Breakfast hotels, some of which are large and have good facilities as well (Movenpick, Sonesta Beach, Hilton etc) but then walk into Namma Bay for the bars and restaurants each night.

I think those temperatures are the worst your likely to get . we always go end March and for the last 2 years we have stayed at the same hotel who put the air and sea temps up on boards . the temps at that time have alway ranged from 25-35 .many days a nice breeze , sun up very early ,sunset around 5pm. its a lovely time to go. Can thoroughly recommend the hilton in sharks bay which is A/I and 15 mins into Naama Bay. chris (doe) is right .I think your brother in Law will first need to decide on one of those 2 choices and then pick your hotel based on that decision

lyn