There's not much scarier when skiing than going over the front of your ski while at speed.
Usually, going OTF can be solved by improving body position and/or tweaking your ski's fin. But, I'd still recommend a different ski. At your weight and boat speed a 67" ski is probably too small for you (I'm 190 lbs and ski at 34 mph on a 67"). So a 68" of 69" ski would probably be better.
I had a Senate once. Good, solid ski, but I couldn't get it to work for me -- my fault, probably because I'm a hack in the slalom course and was used to riding quicker and lighter skis (HO Monza, D3 Nomad). BUT, I've read good things about the Senate and a guy I ski with has run mine into 35 off. So, I don't think you can go wrong with the Senate.