We all have to do this our own way ...The trick with solid copper wire is you have to secure it so it will not vibrate. I've been using some solid copper wire in my bus for almost 4 years now and have read of others using solid romex for many decades without problems. Again, the trick is to keep the wire from flexing and moving while going down the road so that the connections don't break. I used bc cable in order to provide an additional level of personal comfort so that I had a greater chance of never piercing a wire with my screws, etc.
Technically, the marine type stranded cable that many folks like to use, is not approved, as it does not have the UL label. It is approved by the USCG and whatever other marine authorities are involved and is a fine product, but expensive and unnecessary.
What with the price of copper going through the roof you might wish to order your wire/cable well in advance. I'm with FF, I'm using all tinned Marine wire. For the miniscule difference in price....it's forever. I'm seeing in my old '68 model bus that the years have taken their toll on the original wiring harnesses and I'm replacing everything with tinned wire.Here's the best buy I've found:www.waytekwire.comThey're in MN but have GREAT prices...used 'em for years. Get them on the 'net and request a catalog.NCbob
This has been beat to death for many years but I'm going to jump in anyway.Len Silva
Brain, I buy most of my wire from Waytek. I rarely buy 500'. I usually purchase 100' rolls of 14, 12, 10, and 8 ga in almost every color they have available. I have also purchased their various trailer cable in 100' legnths. They also have a great selection on solderess crimp-on terminals at great prices. If call and ask, they will tell you the minimum amount you have to order. I called to order 25 6 ga X 3/8 eye terminals and was told the minimum order was 35, so I went ahead and ordered 35. Jack