Riser on a 00 RMK

I have been riding my 00 RMK 700 with the stock steering height since I bought it 2 seasons ago. Now I want to put a riser on because I find I'm always hunched over and its especially difficult when trying to sidehill etc. I have a few questions. One question is what height is ideal. Right now when standing the handlebars are about at crotch height. Would 3 inch be sufficient? I also don't really want to have to extend any brake lines / cables etc. if I don't have to. Ive heard that at 3 inch I wouldn't have to extend anything. I'm not sure if this is true. I'll have to look further into it. One final thing that has stopped me from putting a riser on before is my snowmobile cover. Parking inside isn't an option for me so I need my cover. Anybody have any luck with fitted Polaris covers and risers. I Don't really want to spend money on another cover or modify my cover. Any input is appreciated.

Riser on a 00 RMK