Eldar are very flexible, so can use a variety of different strategies. In my experience, E-UK Yme Loc are harder to play, and I don't have any experience of the Mymeara list though I agree it looks interesting. That said, you need to pick the troops to suit your style of play.
Unfortunately for most standard Eldar races, you need to take at least 1-2x Guardian formations (to get the Avatar), at least one Aspect formation (for the Avatar which is key) and some Rangers for various roles (I usually take a minimum of 2x formations or 8 units). In Biel Tan that is a minimum of 32 infantry, though it can be fewer in other Eldar lists.
The good news is that the rest of the units are vehicles.
The trick seems to be to pick on a single strategy and build your army accordingly, and on top of that I recommend building in redundancy for the key parts of that strategy (so at least 2x and preferably more of the key formations). Some general comments on other formations
- Personally I find Titans to be a 'bullet magnet' but if that is your thing, Revenants or Warlock are usually preferred over the Phantom (though Phantom and Warlock are pretty much interchangeable as far as models go).
- Vampires and Storm Serpents provide remote delivery of formations but can be hard to use well (because the temptation is to attack something remote from the rest of the army). Failing this, you should strongly consider at least one set of Wave serpents for the Guardians and / or Aspects.
- Falcons are pretty much a given both for AT and AA roles (I prefer at least two). Then add formations to support your strategy - Artillery, Fire Prisms and Scorpions for long range shooting, Jet-bikes and Vypers for mobile support of assaults.
- The Eldar are about the most flexible army in terms of different strategies, and pretty much all formations work well in the right situation - the main exceptions being Cobra, War Walkers and Howling Banshees which are more niche, so I would avoid these at least for now.
Finally, given a limited budget / time / just starting out, I would strongly suggest looking at the army lists in the E-UK site especially those of the top five players (Steve Gullick, Dave Thomas, Richard Laking, Tim Hunt, Joe Jephson). You could also try playing a few battles with proxies to determine your preferred play style.
