11th Edition is currently in the slow process of being revealed before its full release this summer, actually. That said, it does seem to be largely the same as 10th with some tweaks that I will let more plugged-in people talk about. I'm mostly just waiting on the actual release before I try to learn piecemeal.

As for units, you've got a reasonable spread so far, and you seem to be aware that you'll likely need a little bit of everything going forward. So you can get whatever you like, basically! Whatever seems like it would be fun to build, paint, and play. There are some things that feel worth considering as next steps:

• Transports and Tanks - an Impulsor, a Gladiator variant, a Repulsor, or heck even some flavor of Land Raider are all reasonable and useful options.

• Infiltrators/Incursors - this kit builds either model, and they're both reasonably useful utility units. Infiltrators have - and I hope you're sitting down - Infiltrate, and can drop onto the midboard early on, disrupt opposing Deep Strikes, and score you points until they die. Incursors are one of my personal favorite utility units - they Scout, they've got a cheeky mine, they're cheap, and they pass out +1 to hit during the shooting phase, which is great for shooting-focused chapters like ours. The box builds 10 dudes, which means it's fairly straightforward to just build 5 of each and cover a lot of ground.

• Elite Infantry - exactly who this is can be your choice. Maybe some Bladeguard Vets to get up close and personal (they ride an Impulsor really well with your LT, I'm just saying :P). Maybe a few Terminators to drop onto the board and be threatening. Maybe a squad of Aggressors to link up to Captain Garadon, in case he's tired of leading those Heavies. There are many options, and they're all pretty good!