Im currently working on a new team, and ma having a little difficulty with who I should pick for the third. Currently I have a Skarmory, thats used as a wall, and to set up stealth rocks. My second will be a special sweeper in the Form of Hydregien.

After looking into some Pokemon on Smogon, I have decided that my best options, are Gengar and Alakazam. This mainly because they have good SP.Att and Speed, and have access to moves that cover Hydrgien's Weaknesses. The only Problem is, which would be better.

Alakazam, has the better ability in magic guard, making Life orb look very nice. He also has the higher speed, which means better revenge killing. The downsides are, I dont have 10k dream points on B2 and I had to switch systems, so I likely lost all the points on my white game (which actually had 10k dream points). Also breeding may be a problem, cause I would not need to breed for Iv's (SPECIFIC Iv's for that matter) and nature, I will also be needing to breed on ability.

Gengar on the other hand, also has half decent stats. And can pretty well learn all the moves that Alakazam can learn (that im looking for) . He also has a bit more bulk. And Will be generally easier to breed. The only thing is that I wouldnt be using Life orb on him, so I dont know if he would have the Punch I need.

The only problem that they share, is breeding for the right Iv's for HP- Ice.

Any suggestions?

ooh, it's 60 percent? I thought it was lower.

Alakazam is really my first choice, the only problem is getting one with Maigc guard and getting the IV's for HP Ice.

The reason why I said Gengar, is because I have one on hand.

So I guess the real question is, if I cant get my hands on a Female Abra with Magic Guard, Would Gengar be a suitable Subsitute?

Man I've been toiling to decide this as well, I love Alakazam but every time I used him he would come up short so I made a Gengar who honestly seems to perform the same. However all this was before DW abilities so I have not tested a Magic Guard Alakazam, I'll be lurking here to see what other people's opinions are.
My 2 cents are it kind of depends who you are facing, if you want to be able to switch in with levitate and avoid earthquake(which my old team was kind of weak to) or fighting I'd go with Gengar but if your not worried/concerned with that at all than I dont think there is any downside to choosing Alakazam.

Edit: also if you happen to get a female Alakazam with magic guard I'd be happy to trade for one of your eggs

Honestly go with Alakazam. It has higher base speed and base special attack along with access to Psyshock. Both are incredibly frail and will die to a single hit most likely. Plus with Alakazam gaining access to Magic Guard Life Orb recoil and weather damage won't be a problem for you.