There are so many different types of cases and PSU's out there, so I am totaly confused. I am leaning towards a mid tower case but have no idea will that be big enough to provide sufficient cooling. Do you think 650W of PSU if I decide to overclick later. Thank you for your ideas!!!
Please post the rest of your system specs and a budget.
For a PSU, look into a quality Corsair, Seasonic, PCP&C, OCZ or Antec unit.
Depending on the rest of your specifications, you will probably need a 400-550w PSU to safely run your system.
It really depends on how much you want to spend and your aesthetic tastes for which case you should get.
On the budget range I would suggest the Antec 200, mid cost the Antec 300 and the Antec 902 or CM HAF932 at the top.
The general rule of thumb is a high quality 500 to 550 watt power supply with sufficient current (amps) on the +12 volt rail(s) can easily power a system with any single video card made. A high quality 700 to 750 watt power supply with sufficient current (amps) on the +12 volt rail(s) can power a system with two video cards operating in dual mode. There are a few exceptions like the new ATI Radeon HD 5XXX series cards which use less power due to their energy efficiency.
A high quality 500 to 550 watt psu will have a +12 volt rail rated at 40 amps. A high quality 700 to 750 watt psu will have a +12 volt rail rated at 60 amps.
In addition the power supply should be at least 80+ Bronze certified for energy efficiency. There are some models available which have achieved 80+ Silver and 80+ Gold Certifications.
Corsair, PC Power & Cooling, and Seasonic are some of the brands that have a reputation for high quality power supplies that consistently earn high marks in technical reviews. They are reliable, stable, and come with a 5 year warranty. Some of the newer models come with a 7 year warranty. Lately we've been seeing a few other brands offering some high quality units. One example would be the Antec Earthwatts series which is a major improvement over Antec’s older psu’s like the Basiq models.
When it comes to pc cases, selection often becomes a matter of personal preference.
I use the PC Power & Cooling 610 to power my system which is a Xeon x3230@ 3.4Ghz / HD5850/water pump for cooling / 5x120mm fans /4Gb or ram/Blu-Ray player and hard driver..
thanks for the info and suggestions guys. It is my first build and things are going very slowly. So fare I have purchased GA-EP45-UD3R, Q9550 E0 and some memory- SKill 2x2 GB 800MHz. I havent' got a Video card yet witch sould be of a good quality but not overprised as I have got about £ 200 left to buy a case,good SPU and video card.