I would definitely replace the shock and fork springs and put in heavier fork oil. At 300LB, you're overwhelming the suspension (no offence intended). I'm about 200LB and had similar issues. These bikes are set up for around 175LB. The right springs make a world of difference. You'll get a...
Use an FZ1 bar. It'll be the same height as clip-ons and you don't have lower the front end. Plus you'll save a bunch of $$$.
I wouldn't trust my bars attached to an extension, but maybe I'm just a chicken sh!t. All the pressure exerted forwards on the right bar would be trying to unscrew it.
Be sure to read this one too. It's important to understand that an FZ1 bar will get you as low as you can go for a fraction of the price of clip-ons.
http://www.600cc.org/forum/f89/fz1-bar-install-31771/index2.html?highlight=fz1+bars
You can get aftermarket shocks. Search online and you'll find them. You will pay dearly though.
Swap out the springs and use heavier fork oil. It'll cost you around $300 if you do it yourself and it will make a world of difference. If you're going to replace the shock and forks with...
You'll notice it a little (very little) out of the hole, but not once you're moving. I actually find it helps at the track because I can run one gear lower than usual and it makes my laps faster. That, however, has a lot to do with the configuration of the track I usually go to as well.
I do mean pump both parts of the fork several times. There really isn't another way, unless you want to remove the damper rod and let the oil drain out the bottom (not recommended).
When you turn the fork upside down, you need to have a tub under it to catch oil and the parts (spacer, spring...
You'll end up leaving quite a bit of oil in the forks. When you remove the forks, you need to hold them up side down and pump them several times to get all of the oil out.
A triple tree stand is not that much, and you can use it to remove your front wheel for tire changes. That will save...
Check out Royal Distributing in Guelph. You can get a good stand there for not much $. I got a swingarm stand and a triple tree stand from them. The T-Rex spool adapters are a good upgrade if you want the ease of use and stability of spools.
Blue Streak Racing in Embro has a really good...