I'm not a Garage Band hater. I think it is cool. I find it too confining for my work flow is all.
Logic 9 dropped in July '09 and 9.1 was January '10. So while they were very early to support 64-bit they haven't had a major release in 40 months. If they did I missed it. That's pretty slow. I'm no Logic hater. I was an Emagic Logic PC user back in the day and Apple bought Emagic and left me out in the cold. I've used Logic 9. I think it is great. I'm very happy to hear there will be a V10 release. I can't wait to see the feature set. The DAW wars benefits all and who knows they might even convince me to buy.
Going back to the original topic I didn't know there was a work-around for the 48 kHz thing. If it works for you Garage band is very easy to use and projects can be ported to Logic easily down the line if you want.
One final comment on Reaper, you can download it and use it for free. Technically paying the licence isn't elective but it will function without a licence fully featured. They are liberal about it (which I think is brilliant, easier to buy if you can try and it takes a lot of time on a DAW to decide if you love it). If you decide you like it you can pay. Food for thought since it sounds like Garage Band may fit your needs.
Have fun.