First, you failed to mention Laptop or Desktop--kind of critical.

Second, there's really no reason to have Windows 7 Pro for anything you listed. It'll just cost you more.

I doubt you can buy a new computer that won't do everything you want to do.

The last several computers I've bought for home I've just gone out and looked, got a feel for what was decent price-wise and felt reasonably well made and bought that. My own home laptop is actually my old work laptop (a Dell) I paid $150 for or something like that. My wife's laptop, now about 4 years old I paid $525 for (an HP) My shop PC was a bargain priced HP desktop from Staples right about a year ago. I just saw something similar for a great price when I was in there a week or so ago. All run Sketchup just fine for anything I've designed. Even my daughter's laptop, a $400 Acer from Walmart is pretty decent--my only regret there is had we waited another 2 months we could have gotten a nicer machine for that price or a similar machine for $300 as there was a price drop right after.

Problem wise, the Dell Laptop was almost completely replaced under warranty when work owned it. Even some case parts. The HP desktop lost a hard drive which is completely not HP's fault. The HP laptop had an issue with blue screens recently that I thought was a heat issue but it turned out to just be a driver that needed replacing. The Acer has been trouble free other than it won't wake itself for backups much to my frustration. We previously had an Dell home PC that had numerous parts replaced under warranty. Note that I think Dell is part-happy if they are sending out a tech for on-site support. They'd rather replace every possible part that could be causing the problem than send a tech out a second time.

I think 4GB RAM is plenty for what you've listed. Don't buy a more expensive machine just to get the RAM. Its usually a better deal to buy with less RAM, and buy your RAM separately, even if you throw away what's in it.

I don't know what you've got for an office suite now but Office Home and Student is a good buy when purchased with the machine unless you need Access and/or Outlook. Bite the bullet and upgrade as loading an ancient suite on a 64 bit machine is borrowed time. Yes its different and takes some getting used to. If you are using Open Office move to the newest Libre Office on the new machine.