I have to tell you to watch out for this one, the alarm bells aren't ringing all over the place, but the big one is that it's a new site, only created in May this year and registered for one year only.
That alone is enough to cause me concern!
At least it has a genuine email account and as you said, appears to offer good payment options, but is loaded with fakes. that of course is just par for the course, nothing strange about a Chinese site offering fakes for sale.
The payment option of Credit Card would be my choice of payment if you do go ahead, I wouldn't be going with PayPal on this one.
Don't let yourself get sucked in by a sample purchase either, yes it's always smart to look at one product, but to be honest you can't put much credibility on one product.
I think some people get a little carried away with sample products, they get a good one and then put the house on a load. In reality it doesn't take too much to make sure you get a good one for a sample, and a good scammer will do that in an effort top lure you into a larger order to set the sting!
That's bread and butter stuff for a good scammer, so getting a sample is always smart, just keep it in perspective when moving forward.
I would actually contact Alibaba customer support to see if any reports have been filed with them regarding these guys. Support staff here will tell you that it is risky to deal with any business that has been around for less than a year, and the less time they have been trading, the more risk is involved.
Combine that with the fact that it is a Chinese company you are dealing with and the risk is off the chart!
Shop your product around to other suppliers there, find one that offers all the things you require, but one that has stood the test of time and is still trading. That really is a safer way of ensuring you will keep your cash and save any headaches.
The only way I would proceed with these guys is if someone I trusted personally vouched for them, and even then I would ask if they were absolutely sure lol