Hey HardwareExtreme
Personally, what I do to guarantee fitment is download CPU-Z from the interwebs and determine what chipset you have.
Intel says: B65, Q65 and Q67 chipsets are not possible to upgrade to 3rd Gen processors:
http://www.intel.com/content/www/us/en/support/processors/000006050.html
This website will give you an option for selecting a chipset, I have already selected the HM65, and showing you what processors are available that will most likely work with it all are 2nd generation sadly.
http://www.cpu-upgrade.com/mb-Intel_(chipsets)/HM65_Express.html
Also note that you have to select the G2 Socket on the right hand side for these laptops.
According to Toshiba's website, they state we have an HM65 chipset which I believe is the B version. That being said, I found a guy in the comments of another website who did order a 3rd gen and it did not work in his, not even a black power on screen.
the i7-2820QM ($75) was the cheapest quad core model I found on the internet with the best performance. Going up to the i7-2860QM was an additional 50-100 dollars so it wasn't really worth it for the decimal point of performance gain.
Using this website, I found the following quad cores:
i7-2630QM - $40 ebay
i7-2670QM - $45-75 ebay
i7-2710QE - nothing found on ebay
i7-2720QM - $58 - 75 ebay
i7-2760QM - $45-75 ebay
i7-2820QM - $90-150 ebay
i7-2860QM - $129 and up ebay
i7-3610QE
I believe that last i7 however will not work, while it is a 3rd gen, according to Intel's website, it will not fit, and given the comment I found that mentions it not working, I believe it is a website error.
RAM speed and amount supported is determined by the processor here, so order based on what your processor says it can support, not what the manufacturer says. I had these two modules in another laptop so it didn't cost me anything to test it out and as you can see it worked without an issue.
I used the stock heatsink from the i5-2430m. It sits at a constant idle of between 40 and 50*C depending on ambient and the fan is running on lowest setting. If I put it up to a demanding program, it will get up to 65 or 70*C. Most I have ever seen it up to 81*C and that was with Folding@Home running on it full bore with nothing else on. Still well below the 100*C or 105*C limit it has on a very small cooler. The i7-2820QM only uses approximately 7-12w more power than the i5-2430M did, but has a 10W increase over the i5-2430M's thermal design power. If you go up in TDP you're going to need to either get a bigger cooler or remove the inefficiencies on your stock cooler.
Something to consider to boost your heatsink's performance would be to get some 2000grit sandpaper and wet sand the copper contact point for the processor until you can see your reflection, it helps reduce the amount of pits and cavities and increases the efficiency of the thermal paste. That's what I did with mine and it performs admirably with the increased 10w of TDP. I also got good quality thermal grease (MX-4) and pre-spread it on each contact surface with folded stiff postit note so that I knew the entire surface would be covered with the absolute minimal amount required (just enough so you don't see the surface below the grease) which in all actuality is still too much but it has worked better for me than the dot method and a few of the other methods.