Welcome to OC'ing:D
Limits are realitive and vary from chip-to-chip. It isn't rare to see a 3.0 running 3.8Ghz on average. You just have to do the old trial and error and find them. The only place to really be a tenderfoot is on the core voltage and the memory voltage. I'd try everything else prior to nudging up the voltages.
The numbers you are seeing 200/66/33 are the (I'm guessing) the stock settings for the FSB/AGP/PCI. As the freq's of all are set by one clock trigger in the northbridge, you move one (the FSB) and they all move. This is basically when "Dividers" come into play.
Dividers or lock-down's allow you to move the FSB up while either lowering the ratio of the other two, or actually locking them into place at 66/33. By doing this, the PCI and AGP buss is more stable as devices plugged into them usually don't like overclocking at all. Some are tolerant, but not much. Now, raising the FSB with it locked down, you can really rule out these devices as being a fault in an overclock attempt. In other words, read through the manual and find out how to lock down the AGP/PCI bus.
As always, bump up the FSB in small steps. Abit has always been pretty nice in this department as they generally allow at least 1Mhz bumps (sometimes .5Mhz??). I'd say you're a shoe-in to go right to 230Mhz which will shoot you right over the 3.4 mark. After that, you're going to have to study up a bit more and tinker with more advanced settings such as memory timings and voltages. You have a nice setup for experimenting in OC'ing, so I'd just say dig in and learn what you can on that rig. Very nice tool you have there for education!