Share 'Intermediate Disc?'

I am relatively new to disc golf (hence this club). My game has been improving, but I'm a little hung up. I've been using a lighter 164g champion beast, but have been getting a lot of turnover lately. I've tried more overstable discs, but can't seem to get a straight flight - it's a heizer fest. Any suggestions for something - either a disc or technique - that could help me out?