I have used the regular Safety squat bar and it's a good bar. I OWN the YOKE bar and hands down it's a much better bar. BOTH will hold more weight than you'll probably ever use so don't worry bout that. Like Liquid said above the handles on the Yoke bar are removable so you can take them off and hold onto the little stub. The beauty of the safety squat / Yoke bar is due to the camber of the bar the weights make the bar more or less lock onto your shoulders / neck. You dont even really have to hold onto the bar. Yes you would want to take the handles off to do front squats.
On the Spider bar, that is modeled after Ano Turtanian's "KILL BAR" I asked Wendler about it and he said "it has 'issues', to get the Yoke bar and that I wouldn't be disappointed" Well he was right.
The Yoke bar weighs 80 pounds by itself with the handles, 75 with out handles.
Lastly expect to get fucking OWNED by the bar the first few times you use it. If you put too much weight on the bar it will fold your ass up like a lawn chair. The handles allow you the leverage needed to push the weights out in front of you efectively increasing the effect of the bars camber. This will make the movement even harder. An example. When I got the bar I was able to rep 405 8 times for 2 sets. 'Just' 315 on the Yoke bar OWNED my ass....yeah. Prepared to leave any ego you have on the shelf man. Dave Tate wrote an article about the Safety Squat bar and he had a similar experiance. But you build up quickly and are able to do well in short order if you train smart.
If you take a break from using the bar, it will remind you how bad it will kick your ass. But it's a good asswhipping and a very effective tool to have.
Jesup power bars are also a very good and tough bar that's about half the cost of a TPB if money is an issue.
Hope this helps dude,