You are on the right track, but you need to keep researching before tackling this DIY conversion.

It might be a good idea to have a plastic or aluminum tank in the bed of your truck until you get all the bugs worked out of your system before doing a more permanent under-mount tank.

DO NOT use the stock mild steel 2nd tank for your WVO. I'm sure if you are researching this, you already know about polymerization, and that you CANNOT use brass, copper, or mild steel anything. If you had never heard of poly or chicken skin, drop everything and start reading up on that.

As for your tank heating, the simplest solution is a Hotfox or WVO-Designs Hotstick fuel pickup. I've mounted mine horizontally on all my veggie rides, so I get the added benefit of heating my veg in the tank with the whole heated fuel pickup tube.

A brief overview...

You'll need to figure out if you want HIH or HOH or TOT or whatever heated fuel lines. I use simple 3/8" dia aluminum bendable hose, since it's cheap and easy to install.

You'll need a heated filter head, and something that isn't copper or brass. Aluminum or nickel plated works well. DO NOT run WVO thru your stock fuel filter.
Depending on your climate, you'll need 30-50 plates of heat exchangers. It's tempting to use brass since they are cheap, but go nickel-plated.

You'll need a separate pump. There's a guy in the Ford Diesel forum (I forget the name) that sells these at a reasonable price. Duralift something or other.

Lastly, you'll need some selector valves. I use Hydroforce valves and WVO Designs valves. I can usually put about 150,000 miles on a Hydroforce valve before a solenoid or plunger malfunctions. BE SURE to use Viton seals on your hydro valves.

Once again, DON'T make the common mistake of using steel fuel lines and steel tanks.

When installing, splice in your valves just after the Diesel Fuel filter but before the IP. Have the default valve setting on Diesel, so if your system fails, it will default to the stock setup.

Here's a diagram I made a long time ago for my Jetta TDI, but it still applies for my van and your truck, just scale things up.