That does actually make sense now. It's quite usual for companies to only accept wire transfer and initial international orders, especially of that size. Just has you have valid concerns about not having a viable refund option if things go wrong, waht they are trying to do is limit their risk if you change your mind.
Unfortunatly, Credit Card fraud is a big problem and when you're talking about orders of that size, the supplier is usually very careful of accepting a card payment from a new customer. What they are trying to protect against is sending a container load of gear to the other side of the world and then find out that the Credit Card purchase wasn't valid and they have to return the cash to the bank and of course, have lost all their stock.
Unfortunately it's a situation where both parties are looking to limit their risk factors, both you and them and there is no easy solution. Escrow might be a suggestion, where by you pay the money to an escrwo company who hold the funds until you give the all clear to release them. Not sure if they would accept that option, but you might consider mentioning that and seeing if they would consider it.
Perhaps you could also consider a much smaller test purchase to kick it off, maybe a pallet or even a gaylord load just to start. They may even accept card purchase for that, but if not, then you aren't risking anywhere near as much and you can get a good feel for how relaible the merch actually is. Of course that also gives them a chance to get to know you and build some trust, so perhaps that may well be the best way to move forward if you want to.
If you're not comfortable with things like product descriptions and damage ratios being provided, then I wouldn't suggest any sized order. One thing you really need when dealing in this market is a solid open supplier who will bend over backwards to give you as much information as possible.
One dealer I am happy to personally reconmend from my own experience would be VIA Trading. Now you will most lilkely have the same payment issues with them as well, but they have always been very open with me about the stock condition, ratios on loads as so on. So if your not happy with the amount of information TDR are passing through, then you should consider dealing with someone else.
That said, we've had no personal complaints on TDR and they are quite well respected in that market (despite the negative feedback) I doubt thete would be a surplus supplier without some negative feedback, it's kind of a part of that market.
Can I ask what sort of load you are buying, don't need a detailed list, but there are things you have to be careful of when importing surplus from the US. For example, you'll have issues with anything electrical because of our different systems, so things like that you need to be ceraful of.