I like Pike mountain too. There are 3 different ways to the area which can make it interesting, and fun for your brother to check out the BC backroads. You can drive in to Princeton then north on 5A to the Pike mountain forest suervice road. Or you can head to Merrit, then towards Kelowna and turn down the 5A again this time heading south to the same turnoff. Or, my favourite, and fastest way is to turn off at exit 256 (the coldwater exit) just after the toll booth. From there you head through brookemere and along parts of the Kettle valley railway. The last route is very scenic and it is also the fastest.
Once on Pike favourite lakes are Kump, Ludwick, and Johnny.
Nice thing about Pike mountain too is, if you don't get a good vibe about the first lake you stop at, there are another 5 lakes within 20 minutes drive.