I agree with both mtkeller and STBCypriot about not checking electronics especially any that are expensive to replace and that you will need during your stay, damage and theft as I know from experience, can happen and is very upsetting.
As tgtg says 70lb boxes are going to be difficult to handle and be near the size limits, health and safety hat on, so you need to think how you will move them at the start and end of your flights without damaging yourself, hat off. Also tgtg is right boxes might not travel well and you have to take this into account and if using stronger cardboard this is also heavy in itself. It might be easier from a handling and safety, for your items, point of view to buy 2 cheaper suitcases to get around these problems.
Hope this helps
DMF
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A scorpion in Sweden?