If you like the Cheetah id go on Ebay and look for a 2010. It will go up to 30 in. I think the 2011 Pantera is still good and similar to the Cheetah and the Bengal from 2010. You can always resell your 08 Cheetah there. Not sure how much you would get for it?
I hate to consider dumping a bow over the draw length. It's a very reliable, consistant, affordable bow. If I could locate the '10 cam and get a new bowstring I would. Guess it's time to get searching before the deer get moving. Guess if no luck I'm going to have to sell this one and round up a new bow quick!
2x with sonny and barry. some monor modifications would help. but you never did mention what the actual draw length of the bow is with the f7 mod in. thats from the knock point to the deepest part of the grip plus 1.75 inches..... and whats your wingspan? could some of the issue be from improperly set up peep and sight?