Thunderbolt 3 for Precision System Question

I'm considering a precision T7910 or T7920. I'm told that there is the ability to add Thunderbolt 3 to both of these systems with a PCI card.

1. I'm hoping someone with working knowledge of this combination can confirm this would work;

2. I'm told that when you buy the card (this one here? https://www.dell.com/en-uk/shop/accessories/apd/555-beox), it doesn't include the needed cable to connect the card to the header on the motherboard (makes no sense at all) and I'm hoping someone can confirm what cable I need;

3. I can't find any information online regarding how many watts the Thunderbolt ports support. Hoping someone can confirm that.

I came across a Gigabyte card on Amazon that states it provided 100 watts of power through USB-C. I'm wondering if the Dell card does the same? If not, am I able to use the Gigabyte card in the T7910 or T7920?

https://www.amazon.com/gp/product/B07GBZL93X/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&psc=1

Thanks much in advance.