I don't know of a source for a pre-built fuse block. What I bought is a weatherproof fuse block/relay block on Amazon:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
The fuse block that Brendan at LT1Swap uses has bussed terminals, but the one I got doesn't unfortunately. I went with the one from Amazon as it's a wateproof enclosure and has a lot more space and is a complete unit. I'll be using two standalone buss bars with my setup so I don't have to struggle with crimping more than 1 wire onto each terminal at the fuses and relays. One for grounds and one for power.