On the pillow note - I was given a second hand Boppy and I did use it for a little while, but it never fit around me properly. I actually used it most for helping DS learn to sit up
I much rpefer just to use pillow(s) to help position for nursing.
On the side lying note, it is my absolute favorite nursing position! Kayden was able to nurse cradle hold on one boob but could only do the other side in football hold. But he can nurse either side while side lying, and it's actually been the easiest positionf ro him from very early on. It definitely is MUCH easier to learn if you have someone else to help you the first time or two!
I tried on an Ergo baby carrier this past week while I was away. It actually fit me quite comfortably, but the body of the carrier was just too short for Kayden. It only came up to about mid shoulder for him. He's 6 months, 23.2 lbs and 28.9 inches long. It offered no head/neck support to him at all, and he's only going to get bigger!, so I decided not to get it. I ordered the Boba carrier instead. I was holding off because I hoped the Ergo could work (I couldn't get anywhere to try the Boba on so I knew I'd have to order it online). But the Boba has a much longer body, so at least I know Kayden will have some neck support for a little while longer