I don't know about the tubing fitting directly into a 14mm, I didn't think it did, but I've always had a 14mm water pipe adapter. so I may very well be wrong about that one...
You shouldn't need anything special to connect an EQ to an 18mm piece though, the connection between the whip & the EQ (the elbow) is 18mm, and the EQ comes with 2 of them.
1 with a full length of tubing to act as a whip, and 1 with about 10cm of tubing for blowing bags.
Just hook the 2nd elbow up to the other end of the whip, take out the elbow screen & you should be good to go for 18mm pieces.
As for the ssv, 7th floor sell water pipe adaptors in 14mm & 18mm. I think they are about $17 each
I have both of the vapes you are looking at, and IMO the ssv is the better choice. (the ssvis the first vape I bought, so it's kind of my sentimental favourite, so I may be unknowingly biased)
all of the following is my optinion, and not necessarily fact
Efficiency:
The EQ has 2 ways you can pack it, the cyclone bowl, or the elbow pack.
The cyclone bowl shouldn't require stirring, while an elbow pack will generally need a stir towards the end.
I would say that the cyclone bowl is pretty inefficient, due to it's size, it tends to need a bit more in it for satisfying vapor.
Aside from that, I personally don't see a major difference between the EQ & the ssv in efficiency.
Bags:
The ssv cannot do bags, the EQ can, so it wins here.
Whips:
I prefer the ssv over the EQ for whip hits, but I've only used the EQ a few times for whip hits.
(the only reason I bought the EQ was to try bags; I prefer whip hits to bag hits)
Portability:
I'd give the EQ the slight edge, if using in bag mode, as you don't need to find somewhere to put the full whip, aside from that, I'd say they are about the same (I take my ssv over to a friends place all the time)
Heat up time:
Ssv: I'd say 2-5 minutes (the ssv can be left on 24/7, which would eliminate the heat up time completely)
EQ: I'd say 5-15 mins
Reliability:
I would give this to the ssv, as Essentially all it has is a ceramic heating rod, and a temperature dial.
The EQ has a fan, LCD display, 4 buttons, and more complicated internal electronics.
Having said that, I haven't heard anything major about either of them from a reliabilty standpoint, so they are probably pretty close to each other.
Overall:
I would go with an ssv every time, but I don't particularly care for bags.
If you want bags, then I would go with the EQ, if you want a better whip I would go with the ssv.
I hope that helps mike, if you have any questions about either unit, and how they compare, I'd be happy ro try to answer them.