@Notyourmomslx450
CE Auto Electric makes custom cables for a good price - whatever length, gauge, and termination that you want. Great quality too. They also have a ton of nice fuse blocks. Some cost a little (or a lot) more than Amazon, but you get what you pay for especially with waterproof blocks. I've bought cheap fuse blocks and had ground or hot posts shear off when tightening the nut down, I would suggest avoiding the cheap stuff because it's cheaply made.
CE Auto Electric
There's a hot rod shop called On Track Performance on Dartmouth just west of Santa Fe that has battery terminals and covers (and other electrical things). I forget the brand name, but it's good stuff. They're a good place to know about anyway. They've got build your own exhaust pieces, Autometer gauges, brass fittings for water (limited JIS selection but they DO have some), Redline oil, etc.
As everyone is saying, planning things out FIRST is key. Make a map/diagram/schematic and measure distances before buying anything. Especially with the fuse block, mapping things out will tell you how many circuits you need, what type of fuses, etc, and then you can get a block to accommodate all that plus some growth.