If you do want to go with a custom pc vendor, after picking out your pc, DO NOT ORDER RIGHT AWAY. Always save the parts list, and review it with a company representative. Ask them for clearly in an e-mail if those parts have any compatibility issues. If possible, keep a case number for the conversation. This way, you have some documentation that the company says that your parts are fine. If they are not, you have some legal coverage.
For those of you that might want to build your own PC, read on..
For starters, most people don't need a Ferrari for a pc. More computer power does not necessarily equate to more profit trading, and 6 monitors does not mean 6 times the profit. Looking successful and being successful are two different things. Most people don't need more than 2 monitors. If you already have a dual screen setup, are losing money trading, and contemplating upgrading your system, chances are you are still going to be losing money. You'll just have an extra monitor to read about your losses on your statements as you lose more trading.
On that note, if you guys still want some direction in terms of building your own computer, I'll share some knowledge that helped me out. As a disclaimer, I am in no way affiliated with the sites I am about to mention.. just a customer/site user with positive experience.
First off, newegg.com is a great place to get parts for a computer. They have a great refund policy if you need it. The only thing I recommend getting from a store with a physical location such as Best Buy is the monitor. Best Buy generally handles monitor issues (ie: dead pixels) better. Staples is also very good for monitors. Always look through the websites first of the stores since they sometimes have stuff in the store that is not displayed on the floor. Other than that, newegg.com should be just fine for everything.
Next thing, picking out the parts. A great place to learn about computer parts is tomshardware.com. The forums there are especially helpful. They have one section completely dedicated to getting suggestions for what parts you should get given what what you need your computer to do and your budget. The url is below:
http://www.tomshardware.com/forum/forum-31-322.html
If you are going to be building your own pc and ordering the parts, posting your parts list there and getting a review from the community would probably be a wise move. Actually, even if you are ordering your pc from a custom pc vendor, posting your parts on the tomshardware for a review is still a good idea.
Also, check the reviews for all the parts on newegg. Pay attention to the distribution of the reviews. Preferably, you want at least 80% of all reviews to be in the 5 and 4 stare range. For example, if 70% of people rated it 5 stars, and 20% rated it 4 stars, that means that 90% of all votes are int he 5-4 star range. Also, actually read through some of the reviews. I often sort reviews by "lowest reviews" and see what complaints there were, if any. Sometimes, the complaints are idiotic, and other times they are legitimate deal breakers. Also, look at the number of reviews. A product with 1000 reviews with 85% in the 5-4 star range is probably more descriptive than a product with 50 reviews with 90% in the 5-4 star range.
Building your own pc can be rather intimidating, but it is not that bad. A good way to see if you are up for the challenge is to download the manual for the motherboard you plan on buying from the company website. Read through the manual word for word. ACTUALLY READ IT WORD FOR WORD.