I'm no expert, either, other than that I've been shopping cross bikes very seriously the past month. Have you checked your local craigslist? Have you looked at the Fujis? Have you looked at Redline?
Redline has an entry level crosser that retails for $729 or so (at my LBS)...the components were I believe Shimano 2300 which are probably similar or just below Sora. I rode it and it was almost as smooth as say, Tiagra (the next step up from Sora), and it might be just the ticket for what you want. Another of my LBS had a higher-spec -- Tiagra/105 -- Redline Conquest that was on clearance in the $750-850 range. Very nice bike.
BikesDirect also has an entry-level crosser for $499 with Sora/Tiagra and two or three other models that go up in price and specs from there. You may want to take it to your LBS to have them put the headset and front wheel on (which you can do, it's not hard) or at least check it out to make sure the wheels are in true and everything is in proper adjustment (as with any mail-order bike). This can be done for around $50. You could also get a '10 closeout Kona Jake with Tiagra for around $800, maybe less depending on how motivated your LBS is to sell.
As meanwhile said, people have been riding all kinds of components for decades, so unless you're racing it or putting in 20 miles a day, I wouldn't worry too much about "lower-end" components. The weight of these bikes is probably in the 22-24 pound range if that helps.
Cross geometry is a little more aggressive than some other bikes...but all these brands likely offer similarly equipped mountain bikes which you may also like better since you're used to being on flat handlebars and more of a comfort ride. Good luck and enjoy whatever you decide to get!