I want to unlock the legions safehouse to get the lucky shades but I've already recruited boone. I want to keep him so I can get all the companions but I don't know how I can gain enough fame with the legion to get the safehouse key. I'm playing on a ps3 in hard core mode, so no console trickery will work. Is there any way to accomplish that?
Boone will not follow you if you have a positive reputation with Caesar's Legion, however this can be rectified by killing Legion soldiers to get a mixed reputation (assuming you don't want to play as a Legion guy).
You gain fame with the Legion by doing missions for Caesar, or by killing NRC soldiers & Rangers.
Unfortunately having a positive Legion rating will make Boone hate you, which obviously will cost your Spotter perk. Once you are liked enough by one side over the other it is very difficult to switch this around, as most of that group will attack on sight. You can however try wearing armour of the faction you wish to gain influence with, and so long as you avoid guard dogs you should make it to key NPCs.
You can gain easy NCR influence by trading Legion ears to the NCR, and gain Legion influence by trading in NCR dogtags.
Here is a link to a Fallout NV wiki, I have also put the important text in bold here: http://fallout.wikia.com/wiki/Craig_Boone