I got to the US once or sometimes twice three times a year for work (never quite sure how many times). I have a contact in SFO I can send stuff to. I brought a bunch of stuff back with me last time. The only trouble with larger items is it won't fit in traditional luggage. You can go oversize luggage for additional costs, but I worry about damage especially to fragile stuff.
The other alternative is to go with a pallet and ship it, yes you will get stung for import duties with customs but there is no way around this I'm afraid. I haven't shipped anything via a pallet yet, have been looking to import door shells, roof turrets, bonnets, 1/4 panels etc.. But.. I have some concerns dealing with costs on this end. I need to do more research or maybe speak with a broker.
Another option is to source via Japan, I've found some items from Japan are better priced and costs a lot less to ship however this isn't always the case. AUD vs YEN at the moment is sub-optimal. AUD vs USD seems to be better at time of writing.