Vamo isn't a bad set-up and they are relatively inexpensive. The extension tubes have been known to break quite easily at the threads leaving you stuck running only a 350. That's the only major issue I've heard of.
If you don't mind a square mod, iTaste just launched the MVP V2 which is also fairly inexpensive, VV/VW and has an ohm reading.
Both of them are considered VV/VW mods. Mechanicals have no electronics (PCB's) and true mechanicals have no wiring at all, just contacts and a metal body to conduct the current.
You are getting pretty close to 20 posts as well and then you can gain access to the classifieds. It might be worth holding off and finding a used higher end mod.