Thinking of getting a hyper evo 212 because the stock fan im using is quite garbage, but i have a M4A78LT-M and im not sure if it will fit or if it will block a ram slot or not, anyone know if it will fit?
The 212 can be installed either horizontally or vertically. If it doesn't fit one way on your motherboard, it will probably fit in the other.
There is a fair bit of clearance between the contact surface and the first fin so DRAM clearance should not be a major problem unless your DIMMs have excessively fancy heat-spreaders. Since DDR3 DIMMs uses so little power even at 1.6GHz, you could shop around for low-profile DIMMs.
On my P5Q, there is ~1/2" horizontal clearance between my 212+ and the first DIMM slot and a further ~1/4" between the heat pipe and DIMM which has ~1/4" clearance under the first HSF fin.
Since ATX boards tend to share the same general layout between CPUs with integrated memory controllers and HSFs are designed with each manufacturer's keep-out zones in mind, the 212+/EVO would most likely fit.
Depends completely on your ram and where you want the fan. If you have high profile ram like the vengeance series, then be prepared to put them in different slots.
However, if you don't plan on having a push/pull fan config, then you could put the stock fan on the other side so it's pulling air through instead of pushing, which would allow the ram to be as high as you like!