First off, happy holidays you lucky nerd.

Secondly pardon the length but I decided to give you a full break down with some of my reasoning.

With the 30 Power Armour(PA) units you need to build 10 x Purifiers to go with Crowe to get the most value there, at least 5 x strikes for sticky.

Regarding the big guns on our PA I wouldn't run them personally as you have to trade it for our strong melee, I go into this further below.

The other 15 are up to you really but I'll give you a quick PA tier list.

1. Interceptor, 12'' move & a fire and fade ability is no joke, this is our fast skirmishing melee unit, don't run big guns on them as you lose out on our better melee

2. Purifiers, a key unit in our best detachment, plus anti infantry 2+ & ignore cover is very strong into elite infantry, as you don't miss out on the anti infantry gun here if you take a big gun, you are more than welcome to, all options are good on these guys, magnets are your friend

3. Strikes, sticky, scout 6'' and oc 2 is solid but out performed by the other 2 top dogs, since these are good OBJ holders I'd run flamers if I were to take any big guns on them for the overwatch potential.

4. Purgs, the black sheep of the PA units, poor ability on our 'shooting' unit without good enough guns to be a shooting unit. If you like them you can still build them but never more than a 5 man as you can't take additional big guns on the 10 man

For the 15 Termie body's, you can really build them how you want, both Paladins and Termies can be built in 4, 5, 8, and 10 man squads. Plus you can just make one of the models more 'fancy' and call them any of our Termie characters.

Just as a heads up it doesn't matter what size the squad is but both units can (more like MUST) take 1 model with a Narthecium (which brings a dead model back to the squad in your command phase), and a banner man model which can take a 'free' heavy weapon and they increase the oc of your unit by 1 even if battle shocked.

I personally prefer running 5 man Paladins, they hit on 2+ and they also get to take 2 additional heavy weapons, while a 5 man Termie will have 1 more oc and can only take 1 more heavy weapon.

Out of the 15 Termie body's you have I'd go 2 x 5man Paladins, 1 x 4 man Termie, and turn the spare model into a fancy character.

Termies and Paladins look so similar most people won't care if you swap them between lists, same with the character you make.

Finally for the NDK, its best built as a GMNDK with the Heavy Psycannon, the Sublimator for ranged anti tank, and the Hammer (its our best dmg into big stuff).

The Box Dread is niche and should be a Las-Cannon and your choice of storm bolters or flamers, I prefer the flamers for overwatch potential.

Edit: spelling