I haven't at all tested this deck, since I'm missing about 8 of the cards,
but I wanted to know what you thought of it.

Pokemon:
4 Promo Mewtwo
4 Dratini
3 Dragonair
4 Ghastly (fossil)
3 Haunter (fossil)
2 Gengar

Trainers:
4 ER
4 SER
3 Comp. Search
3 Item Finder
2 Prof. Oak
4 GoW

Energies:
16 Psychic
4 DCE

    It's a psychic deck..it's an energy removal deck..it has a way to make 40
damage starting turn 2..Glad I thought of it..
The idea is to beat down opponent by denying energy with ERs, SERs, and
Dragonair, or if you're lucky enough, start off with a mewtwo, put a psychic
energy down 1st turn, comp search and discard 2 psy energies, oak, then use
Mewtwo's energy retrieval attack and attack on turn 2 for 40 damage.  Ghastly
works to help dragonair with energy in case you have to use some in SER.
Haunter is a somewhat useful stop on the way to ghastly becoming Gengar, and
Gengar can help kill off those annoying low retreat/high hp pokes.  Item
finders can help you discard energy (for mewtwo) to get back that SER or
maybe just that ER to help keep damage offa mewtwo.  All in all, it ought to
work pretty well, but I haven't tried it out yet..

 
    You have done something very few decks have. This deck scares me! I do see some problems with it though. The main problem is the 20 energy total. IMHO, that is way too little energy to play in any deck, but it might work. To it though, the speed needs to be juiced up a little.
    Here's what I might do. Loose 1 SER and GOW, and all the Comp.Searches and Item Finders. In their place, put 2 Bills, 3 Pokemon Traders, and 3 of either Psychic Energy, Energy Search, or Energy Retrieval. The Bills and Traders should be able to help you get what you need without a problem. The reason I'm giving you a choice on the last part is simply because any of those three options should work, depending on your playing style.
    See if this helps at all.
    Bryan Howland, Deck Mechanic