You really don't have to worry about a cooler fitting with most mid size cases.
The cm hyper212 is 160mm tall(6.25") It is a good value cooler.
The Antec 300 case is 8.1" wide so the cm should fit easily. Some cases with side fans may be a problem, but I am not much of a fan
of side fans.
The Noctua NH-D14 is also 160mm tall, and is probably the quietest and most efficient air cooler you can buy today.
The Prolimatech megahalems is also the size and is one of the best. It is particularly easy to install.
Actually, the only tricky coolers are the push pin coolers like the stock intel coolers.
If there is any trick to mounting coolers, it is to do the job with the motherboard out of the case.
I use a paper coffee filter and alcohol to clean off the thermal grease. Arctic silver sells a two vial cleaning kit if you want the best material. Their as-5 is very good thermal grease.
The Antec 300 also comes as the illusion model from newegg, but is temporarily out of stock. It comes with two added front fans.
http://www.newegg.com/Product/Product.aspx?Item=N82E16811129066
It is no big deal to mount fans. Download and read the case manual to get an idea of what is involved. The motherboard manual too.
Noctua probably makes the best fans, but they are expensive. Look for yate loon as a good inexpensive fan.
http://www.amazon.com/Yate-120mm-Model-D12SL-12-Black/dp/B000CHU9UC