1. First off, consider using the FSP 300-60GHS-R 300W PSUhttp://www.newegg.com/Product/Product.a ... 6817104075
It is a good PSU. It is 4.92" x 3.94" x 2.50" (it has a special bracket that permits it to mount as a standard ATX PSU), and it will give you an extra 0.9 inches of clearance.
2. The AXP-140 RT is a good heat sink. It is 70.2 mm high. A 25mm fan brings that to 95.2 mm. And you then want 25mm of breathing room, which brings the entire package to 120.2mm.
3. I have a Q07 with a Samuel 17 and a nexus fan using the FSP 300-60GHS-R 300W PSU. It handles an old high end 775 quad core CPU just fine. And it has plenty of clearance. My quad core Intel 9550 kicks out more heat than any of the modern Intel CPUs.
The Samuel 17's effective Height, with 25mm of breathing space for 25mm thick fan, is 95mm. The heatsink without a fan is 45mm high.
4. At the moment I think the best option for these Lian Li cube cases is the Noctua NH-L12. See:http://www.silentpcreview.com/article1270-page7.htmlhttp://www.silentpcreview.com/article1261-page6.html
The Noctua NH-L12 actual height with just the bottom fan is 66mm. If you are using just the underfan, you don't need the extra breathing space for the fan, it's built in.
If you add the top fan, you reach a height of 93mm, plus 25 mm of breathing room for a total height of 118mm.
But the performance with just the underfan can handle any current generation Intel quad core, unless you intend to overclock it. And it might even handle that unless you get too extreme.
I'm not certain which is the top performer, the XP 140 or the Noctua NH-L12. They might be about the same. But I think you will find the NH-L12 to be more flexible in terms of your installation options. Also, we have a new generation of chips coming out in 6 to 8 months and Noctua has always maintained a policy of providing new mountings for new chips to its customers... all you have to do is save your receipts to prove you are a customer.
5. If you want a real hunka hunka cooler that has more capacity than the 140, consider the Noctua NH-C14 with just a single underfan. Its total height with one bottom fan = 105mm. And because it uses an underfan, it doesn't need any breathing room on top. I would run it with just a single 120mm Nexus underfan.
Though I think this is much more cooler than you need.
6. For more info on short stature cooling options see:viewtopic.php?p=539859#p539859viewtopic.php?p=538745#p538745