The biggest issue with doing it is the time it takes. Some of the compiling can take ages, and you tend to forget you are waiting for it, and get busy with something else, only to come back 3 days later with no idea what stage you got to!
My advice is to use the fastest machine you have as the host for the LFS build process - it'll take a lot of the pain away.
Well, the ultimate achievement when building an LFS system is to plug it to an existing package manager so you don't have to keep updating stuff manually.
Probably easiest to start with ubuntu.
LFS walks through isolation when you are building the system, so it doesn't really matter what you start with.