Seriously, mate, the most astonishing thing about you has to be your modesty. With all that smartness, I think you're being too modest.
You code? What do you code, exactly? "Hello, World!"?
You do photography? Oh... well... I have friends who are 11 and work some awesome things in Photoshop.
Fix computers? Yeah, well, it's not that hard to reinstall your aunt's Windows and go around saying you're awesomely smart.
Also, how come someone like you, how deals with a lot of computers and fixing, even coding (driver coding, I'd say), has such a hard time deciding over a machine, and needs the help of some averages, less than mortals?
No offense meant, but someone who is really smart would never go around saying it all over the place. I know the feeling. When I knew <html><head><title> I was astonished by how much I knew. After digging a little deeper, I found out about CSS, standards, and so on. I was feeling rather... retarded, and I burst into laughter. You look exactly like those guys who appear on MTV while having orgasm, going around and b**ching about how cool they are.
And in order to stay on topic, it's entirely up to you. Unless you've got three additional hands and 3 additional brains, it's hard for me to believe you code, fix computers, do photography, talk over the phone with two people, ALL AT ONCE, so any machine, even an iMac, would do just fine for all your tasks. Upgrade it to 1TB of HD space, and buy yourself external HDDs as you fill the others.