Yep the 4gb on whatever processor is a good idea. Using iStat to watch usage I never get close to being maxed with the 4GB for the every day tasks and nothing hangs or is slow.
On the damn Time Capsule I have now it seems have 3 crap options...send the brand new thing off to service (which they claim will take 2-4 weeks)...throw it in the trash...or get a lawyer and end up with higher BP and more stress over the issue. I know this can and does happen with any brand but it quickly wiped the new Apple user grin off my face. People are getting brand new computers as replacements for much less obvious issues and I can't even get a working product. I now have zero confidence Apple will makes things right if I have anymore issues. I like the OS and I like the products when they work but I now see they are not any better than the things half their cost in the end.
But really Apple is pretty smart as a business...they got my money with promises of being "better" and "just working" and in the end that's the goal...profit. Bravo Apple...trade a one time couple grand profit for a potential lifetime customer. After this laptop dies (and I hope to god it lasts a reasonable amount of time) it is back to cheaper just as unreliable options for me. That didn't take long