Most stores have a small transfer fee - somewhere between $15 and $25... The store you ship it to has to be registered with the site though, so you'll have to contact the shop and let them know you have something coming. If they aren't already registered then there's a little bit of a process, but the website can explain better than I can. Don't worry, it sounds complicated, but it's not - and if you call the store the folks who work there are very friendly and helpful.
I don't think it would be a bad idea to start with a .45 at all, especially if it's for home protection. If you have fired a .45 already, and liked it, then that should be good. It's important to get what YOU want! My girlfriend has become quite a good shot in the last year or so. She started out on my 1911 - a .45ACP.
What I will say is that eventually, you should get a .22 for practice. I know it's not the most thrilling idea in the world - I fought it for years! I'm hardheaded...
I bought a 9mm to practice with instead, and got very good out to about 45 feet (15 yards) - that's OK for self defense. But I realize now that my shooting will never get better without one. I learned to shoot well with a .45 - but I want to take it to the next level now, and a .22 is the only way. In the meantime, I say get what you want. You have time for a .22LR if you're like me, and want to get a bunch of big guns first.
Caliber...
I could start a war with this one... Really, regardless of my own personal predjudices and biaed opinions, anything bigger than a 9mm will work. The general opinion, and I agree, is that anything 9mm (which is actually around .355" caliber) or larger will work just fine with good ammo for self defense.
Sigfan, do you use the large grip, or the small grip? FWIW, my hands are HUGE, and I can't stand the large grip on my SP 2340. The small grip looks tiny, but it's a perfect fit for me. My girlfriend, who has tiny hands, likes the big grips. Go figure.