Hi BurntPain,
Sorry I'm late getting back to you but at 78 there just aren't as many usable hours as there were. My trikes are not the usual ones. If you look just next to your comments you will see the Indian Tri Car post. That is mine. Gas powered and the build thread is a long one. I had a bone infection show up in late 2013 and I'm still working with the aftermath of that which left me with severe arthritis.
Not much has been done with it in a long time though after a lot of false starts I hope to have it going soon.
This is the bike that I'm working on now. It's in the electric trike thread. Thread is named the The Epic an electric tri car. Why build something simple when you can complicate your life.
While I'm waiting for the parts to finish the Indian tri car I decided to build a vintage style electric tri car of my own design. It's started but due to our usual fall monsoon rains here in British Columbia I can only work a day or two every week with luck and it looks like next Tuesday will...
motorbicycling.com
Costing a build is hard because I'm in Canada and with the dollar difference the prices are different. Much more expensive here. I will over the next couple of days link you to sites I have found over the years.
If they were talking about 10 units or any set number of units you most likely were looking at AliBaba. That is their wholesale site. Look at AliExpress. This is the retail site. You can buy any number of products you want. For batteries and related parts I buy from the LiitoKala Official Store. They have proven trustworthy and make sure you are at the Official Store. Lot of resellers buy from them and don't back up their products.
Check to see how long a business has been there and their approval rating. Number sold of the item your looking at and the number of stars on their site. If they sold 2 or 3 I usually keep looking.
To contact a business look at the top of their page for their information. Email address is usually there if not on the page it's self.
When I first started building bikes I built a bike with a side car that was electric. I bought everything from a local company and it cost me far more than it should. If I were to build your trike the quick and easy way out would be a hub motor front wheel and a 48v/52v battery. If your doing a lot of riding probably a 25Ah/30Ah battery. The more Ah or amp hours the greater the battery capacity.
Look at the Ebike School. He will teach you a lot.
I'll be back to give you more information and I'm sure others will add to it.
Steve.