There company is only a hour and a half from me here in Idaho. Send them an email and they will give the answers on anything you need. https://www.teamtekin.com/index.html
Tekin is the best imo and yes the covid shortages on everything are to blame. Before covid they were never sold out. for an 1/8 scale buggy Id definitely go RX8 as for motor depends on what size lipos you plan on runnin' and what size track you're gonna be on. On 4S which is common around here Id probably go 1800 or 1900kv medium sized normal course. Smaller courses Id go something like 1700kv, really large courses where you can really get some speed going Id probably go 1900 or 2050kv