Fuel piping question

Time has slipped past and I am finally ready to run my fuel line up to the engine compartment. I've studied many posts about fuel lines but have not found one that really details what you have done going thru the frame where the trans cross member bolts to. I was thinking about drilling and using grommets but was wondering if there are any other better ways. I see many members here have sectioned the lines in 2 or three pieces. Is that in case you have to replace or service something or just because it is so hard to run a one piece line from front to back. Looking for suggestions!
Thanks Rod