Here's my advice.
1 - The Triarch Stalker is an odd Cog in the Necron Machine. I'll agree with Hollis that is is drastically overcosted for what you get from it. The short of it is that we end up paying more than a Dread, we only get 1 weapon, the Armor gets weaker the minute we take a Penetrating hit, and we don't even get Dread
CCW if they actually make it into combat. That doesn't mean it's not worth taking, you just have to build a list around them. They become incredibly more effective with the more infantry that you run, so they become really good on Warrior heavy lists. Your Nightscythes and ABarges are already Twin-linked so won't be able to make much use of it. I own two of them and have had several games with them and they're great. What they need is a distraction, which you're actually accomplishing with the 2 ABarges. You're opponent is effectively going to have to choose how he wants you to kill him.
The HARDEST part with the Triarch Stalker is picking the Weapon. Both the Heat Ray/Particle Shredder have their strengths, but after a few games having the same Range as the rest of the Army felt limiting to me. I really struggle with the points for the Heavy Gauss, but I have not regretted it whenever I have fielded it. It gives you that little extra range without affecting the movement or firing of the Warriors, and the Twin-linked helps insure you get a hit, which is what you're really going for. I strongly recommend trying each of them out to find out which one fits your play style.
2 - Whip Coils - I disagree with them altogether so you might consider dropping them. They just aren't worth the points. Your opponents will quickly learn to just park stuff in cover, and not worry too much about the unit, especially with just 3 of them. You really only want them in a unit when there is a D-Lord present, as this makes the D-Lord effective, and not necessarily the Wraiths themselves. (I also HATE it when I see this unit on lists, as it's probably the 2nd biggest waste of points next to running Lychguard!) At least people haven't recommended you do this here (yet...), and it's just fine.
3 - Gauss Warriors are the way to go if you're going to put them in the Nightscythe. Gauss, from my experience is just a better weapon all around, but I see the attraction to Tesla. With a Nightscythe, you'll be able to deliver those 10 Immortals into Rapid Fire range. 20 S5/AP4 shots is something that not a lot of armies have a counter against, and if you back it up with the Triarch, they'll finish off pretty much anything they shoot at.
With that in mind, here is a list very similar to what I run, modified to fit what you said.
Overlord - Scythe/Weave/Orb/MSS (With Warriors)
*Lord - Scythe/Orb/Weave (With other Warriors)
Triarch Stalker - HGC
17 Warriors
17 Warriors
10 Immortals (Gauss)
*Nightscythe
5 Wraiths
ABarge
ABarge
There are some points to play around with but that's for you to decide. You can free up some points easily by changing the weapon on the Stalker, and dropping the
MSS. Im only recommending the
MSS since it's good that you learn how to use them as you learn to play, but they won't do much on the turn you get charged being in a huge block of Warriors. Feel free to shift/add/remove Warriors around as needed, but I'd strongly recommend not going below 14 to benefit from both the Stalker, and being extremely survivable. The Overlord and Lord should be some where in the middle of the units to soak wounds should the unit be hit hard, this will help keep Warriors up to make the
RP rolls. 5 Wraiths make it at least as effective as a
SM Assault unit. Extremely resilient, and enough of a threat that your opponent can't ignore them adding to the 'How does my opponent want me to kill him' feeling.
Hope this helps give a different perspective on Necrons, and helps you with what you're trying to do.
EDIT: I know you don't WANT to use them, but I thought I'd chime in on 2 of the units you do not want because they do combo well with the Triarch Stalker, and might be worth a look down the road, but you don't need them.
*Monoliths are great, as they still provide distraction for keeping the Triarch Stalker alive, and can deliver one of your Warrior units into Rapid Fire Range. The Warriors backed up by the Stalker will deliver a powerful blow. We didn't talk about Characters, but if you try out Zahndrekh, that Monolith along with the rest of the Army becomes extremely versatile on the board.
*Tomb Blades. These guys with Particle Beamers are a perfect match when teamed up with a Triarch Stalker. They are fast enough to keep up with the rest of the army as you annihilate your opponent or can get around to meet any counters your opponents might have.