It is time to upgrade. I need some good advice.

[MiRai]

- Will my current rig be able to handel those upgrades? I think my power supply is good enough for it, but I am not positive.

Yes. A 1200W PSU will handle a hefty overclock on a modern CPU and triple SLI using top end video cards.
I'm going to guess that your current system uses maybe 650W at most.

- Would I have to add anything else new above and beyond what i have listed above for heat issues? With the case I have and current cooling will I be ok? Will that much ram get much hotter then what I am currently using?

No, but I wouldn't recommend buying the equipment you listed (see below). RAM doesn't usually get hot
unless you overclock the shit out of it and/or pump a ton of voltage into it.

- Are their better parts to put into my rig, at better prices then the ones I listed above.

If we're talking price:performance ratio then, yes.

Intel 2600K @ $325 or Intel 2500K @ $230
$200 1155 Motherboard (ASUS, Gigabyte, EVGA)
$150 16GB RAM 1.5V (Corsair, G.Skill, etc.)

If so please tell me why and which.

The 1366 chipset is old news at this point and about to be completely obsolete now that X79 has launched
and Ivy Bridge is coming out later this year.

- Should I add a SSD at this time

As it stands, the answer to that is up to your budget. I will always recommend an SSD (64GB or more) if
you can afford it.

and would it work ok with the board I selected?

If the motherboard you buy has SATAII or SATAIII (preferred) ports it'll work just fine.

Is there enough of a performance boost for multiboxing to worry about getting one, over the pair of raptors I already have in my rig?

Yep.