I prefer the peep sights of the No 4 and find them alot easier to use. It also has a heavier barrel. The No 1 rifle though is still a lovely classic and well worth getting, especially Lithgow made ones. It is a more complex rifle with more luxuries than the No 4 does and has more variation.
Interesting enough some Lee Enfields are still used professionally around the world after all these years.
You might want to look into an Ishapore 2a or 2a1. They are built on the No 1 SMLE design, but have stronger metal alloys to handle 7.62mm NATO rounds.
Either way, as soon as you get one you will end up like everyone else who collected just one. With a dozen or more rifles of all the various types.