I have an 01 RMK 800 SP 144 and I am in bad need of a new track. I would really like to long track it to either a 155 or 159. I found a good deal on a brand new 159 track, but I have zero experience on extending a track, so I have a couple questions...would I just need the track, rail extesions, and a tunnel extension? How long of a track can I run without extending my tunnel? Anything else important to know when changing a track/long tracking? Thanks!