I would definitely suggest the Ella
as your first. It gets nothing but glowing review after glowing review for G spot stimulation and I think the material (silicone) is a little less intimidating than steel and wood (the materials of the above toys). It's also significantly less expensive than those two toys so if you find out it didn't work for you it's not like you've lost over a hundred dollars in the process.
As a side note, I hope you'll remember that G spot orgasms aren't the be-all-end-all of orgasms. I have G spot orgasms and I personally enjoy strictly clitoral orgasms just as much, so there's no need to put undue pressure on yourself to have a G spot orgasm. That said, have fun experimenting and good luck