What's your estimated power output and boost level? A more mild build may be able to run one of those inexpensive 340 lph pumps.
TI is the same as Walbro - I'm running one of their 255 lph external pumps for a turbo slant six, but it's likely a built V8 may need two of their pumps. I've seen a lot of fake Walbro / TI pumps turn up on Amazon, and worse, Amazon often tends to dump them all in the same bin so even one from a reputable seller can be bad there. I'd recommend getting one from a vendor that understands the problems of a contaminated supply chain.