Okay, when you decide to go with a SFF your going to run into several issues:
* Heat is the #1 problem in smaller cases, so you'll need a good design and room for good airflow.
* GPU size and power requirements are going to limit what you can use.
* PSU size (physical size) is usually the biggest problem in a SFF. Most SFF cases don't allow standard ATX PSU's, so that becomes a real big issue. If you have a case that can fix a standard PSU than your better off, especially if you need to replace it later.
* You are usually limited to a single DVD/CD, 1 FD slot, and possibly 1 or 2 HD's, depending on the case.
* You will have limited space for a CPU HSF, so keep that in mind too.
My recommendations for a SFF build, depending on the case size and limitations:
* You'll be limited to 1 GPU and that will be more dependant on it's physical size and it's power requirements.
* Try and limit the amount of drives and additional cards. This will minimize your power needs and also allow more airflow too.
* Stick with SATA drives at all costs. This will allow more airflow!
* You might consider using a lower power CPU. This will generate less heat and also consume less power, which will leave more for other parts too (mainly the GPU).
* I'd consider getting Vista Home Premium 64 bit over XP 64bit, unless you have some programs that don't run on Vista.
* I'd start with 4 gb's of DDR2 (DDR3 is only needed on the newer i7 core systems).
* Stick with a quality PSU (Corsair, PCP&C, Seasonic, & Antec are good ones) and one that is at least >80% efficient. This will minimize heat and probably noise too. Modular PSU's might be considered, since this will minimize the cable clutter in the system and will allow more airflow too!
With your expected budget you could even get a very good Laptop for around $1500-2000 USD or so, which would be well under you budget. The nice part is you won't have to tote around all of the SFF parts with you, it'll all be within the laptop (LCD, case, power connectors, etc.).
Thanks alot lunyone for taking the time to write the very informative post!
The cases I have looked at, the Sugo 01 and Sugo 02, supports "regular" sized PSU's, so that hopefully won't be a problem.
I will only use one HD, and also only one DVD drive. Dont really expect anything else in there, as you say, to try and get the heat decreased. Will definitely go SATA, thanks for the tip. Also will try to see if I can find some motherboard with onboard sound, so I dont have to get an additional pci soundcard, taking up space and increasing heat (not a big sound connoisseur anyway).
GPU wise, I will most definitely go for a single card. Just dont know yet whether to get the HD 4870 or Geforce 260/280, dont even know which motherboard to use yet, but will hopefully get some time today to get more into the latest matx motherboards.
As for ram: Excellent, I didnt know at all that the DDR3 was only for the i7 systems.
Regarding the laptops: Im in Denmark and they are really quite expensive here. Checked a couple of weeks back, and for 1400 pounds I could only get one of the more limited editions of Toshiba Qosmio. Even though its a nice PC and definately more easy to lug around than a SFF PC, it just doesnt cut it spec wise (believe it only had a geforce 9600 GT, 9800 or similar.
All mobo's have onboard sound of recent years, so you can use the onboard sound (which is generally quite good!).
DDR3 isn't limited to i7 mobo's, but you should be looking at DDR2 memory for your build. Comparison for some Micro ATX g45 based mobo's.
Size of GPU's to consider:
Card Dimension 12.5 x 24.6 cm (HxL)
gtx 260 (216 core)
Card Dimension 11.1 x 26.7 cm (H x L)
Card Dimension 11.1 x 26.7 cm (H x L)
So if you have the room, the gtx 260/280 are the same length, but if you don't have the room, you'll have to consider the 4870 GPU, since it's a bit shorter in length. Just make sure you get a Double slotted GPU (like shown below), so the hot air will be blown out the back of the case, instead of being blown around on the inside of the case and then eventually being pushed out by the case fan.
I think the Silverstone cases that your looking at are probably good choices. I'm not sure what is available in your area, but Silverstone & Antec seem to make good quality SFF cases, so keep that in mind.