The Heavy Support choices in the Eldar codex are very good, and having to make choices of which ones to fit into your lists is not going to be easy. So lets take a look at two more options, the Falcon, and Fire Prism. Both at first glance make excellent choices.
The Falcon, comes with a Pulse Laser, which I really like, and has many options from Starcannons, to Bright lances and scatter lasers. So the Falcon has a good array of weapons that can fit into your lists, and in some situations I can see the Falcon being your top choice.
Taking a Crystal Targetting Matrix allows you to move forward while going flat out and still be able to fire a weapon. This is huge, and is how I see this vehicle being used. Side armour shots on vehicles is precious, and when you can get two pulse laser shots into the side armour of a chimera, its priceless.
Not to mention that Holo-fields gives you a +1 cover saves, so we all know how resilient these eldar vehicles are. At BS4 this is a an excellent vehicle for the point costs.
Here is the issue. The Fire Prism is probably your best choice of the two, which will keep the falcon in a second choice role.
The Fire Prism costs the same as a Falcon without any upgrades, has extremely long range (60"). So overall the Fire Prism will be cheaper, and its Prism Cannon is extremely good. 60" Hvy 1 with 3 modes of fire.
Dispersed: S5 AP3 Large Blast
Focused: S7 AP2 Small Blast
Lance: S9 AP1 Lance
For a very inexpensive vehicle, 125pts, the Fire Prism is an amazing vehicle, but I would be adding holofields to it.
Eldar have no search lights.
There is one tactical issue with both vehicles though that few people are talking about. Night Fighting. 50% of your games are going to start off it in, and the best way to get night vision on your heavy support choices is by using Dark Reapers. Night Fighting will negate the tactical side of having such a long range weapon for the Fire Prism, so opponents will be seeing cover saves, and the same goes for the Falcon having to be in closer.