Zoids products can still be found, but mainly online - usual suspects: eBay, Yahoo! Japan, HLJ, etc.
When buying from overseas, I agree one of the deterrent for me is the *possibility* of getting TAXED by Kastam. Happened twice to me and had to fork out extra 3-digit funding!
Anyway, if I can support Local, I will but, sorry to say, not much Zoids choices now.
Khai62Don't forget to give mini-review when you build that MSS Sinker, ya? Also, be careful with the tiny parts. I think a ZP member lost a piece in their shag-pile carpet.
spacelionNon-working Dark Horn? If you're not scared to try, you can open up the motor casing and slooooowly *shake* the gears while the motor is switched ON. This technique helped to revive some of my old motorised Zoids. Just don't loose or misalign the pieces after you're done.
About your Zoids, I am guessing you have the following:
No. 1. Special Edition Dark Horn

My one and only Dark Horn is this itty, tiny baby Evo-Drive wind-up:

(http://www.flickr.com/photos/ridertekran/8181436928/)
No. 2. Gore, the Lord Protector

No. 3. Salamander

(p.s. mine got "kissed" by rats long, long time ago...so sad)